Calculus 1 : Equations

Study concepts, example questions & explanations for Calculus 1

varsity tutors app store varsity tutors android store

Example Questions

Example Question #231 : Equations

Determine  given that .

Possible Answers:

Correct answer:

Explanation:

This problem is asking you to find the indefinite integral of the given function, f'(x). To do this, we need to work through the function one term at a time. For each term in the function, we perform two steps. First, we divide the coefficient of that term by (n+1), where "n" is the value of the exponent for that term's x-value. Second, we add 1 to the value of that term's x-value. We continue this process for each term in the function. 

So, for , this would look like

 

which when integrated will equal 

You must remember to include "C" in your final answer; this acts as a placeholder for any constants that may have been present in the original equation.

Example Question #1282 : Functions

Determine  given that .

Possible Answers:

Correct answer:

Explanation:

This problem is asking you to find the indefinite integral of the given function, f'(x). To do this, we need to work through the function one term at a time. For each term in the function, we perform two steps. First, we divide the coefficient of that term by (n+1), where "n" is the value of the exponent for that term's x-value. Second, we add 1 to the value of that term's x-value. We continue this process for each term in the function. 

So, for , this would look like

 

which when integrated will equal 

You must remember to include "C" in your final answer; this acts as a placeholder for any constants that may have been present in the original equation.

Example Question #2312 : Calculus

Write the equation that shows how a mass of atoms  decays over time if it's half life is  days, and initial mass is . Assume  is in days. 

Possible Answers:

Correct answer:

Explanation:

We know that since its a half life question, the exponential used will be:

 where  relates to length of the half life. Since the half life is 3 days in this question, 

Since we know how the mass is decaying over time, we simply need to put our  and  properly such that:

.

To check, if you plug , we get that , which indicates that we've lost half the mass in 3 days. 

Example Question #1284 : Functions

Determine the first order differential equation that is solved by:

Possible Answers:

Correct answer:

Explanation:

To determine this, we take the derivative of 

If we set , where  is a function that sets the two sides equal:

Notce that if we multiply the right side by , and set , we get that:

Backtracking we get that:

 

Example Question #1285 : Functions

A very important physics formula is called the continuity equation. We will only consider the 1-dimensional continuity equation for now. 

In the continuity equation, we're given that:

, where  is a function of  and .

Reduce the continuity equation to its most simplest form, such that one side of the equation is 

Possible Answers:

Correct answer:

Explanation:

Although this may seem difficult, since both sides have identical integrals, we can just compare what's underneath the integral. 

Moving to the right:

Example Question #231 : Equations

We're told that  by Newton's 2nd Law, where  is force,  is mass, and  is acceleration as a function of time. Knowing the relationship between acceleration and position , write Newton's 2nd law as a second order differential equation. 

Possible Answers:

Correct answer:

Explanation:

We know that:

, since acceleration is the 2nd derivative of position. Knowing this we plug this into the formula to get that: 

Example Question #231 : Writing Equations

Write the equation of the line tangent to the given function at x=2 in slope-intercept form. 

Possible Answers:

None of the other answers

Correct answer:

Explanation:

The equation of the line tangent to the curve of f(x) at x=2 will have a slope equal to the instantaneous rate of change of the curve at x=2. In other words, the slope of the tangent line will have a slope equal to the derivative of f(x) defined at x=2, namely f'(2).

To solve this, we have that

  ;  

  ;  

To get the equation of the tangent line, we must use the Point-Slope formula utilizing the slope obtained from the derivative and the point of tangency.

The Point-Slope formula is defined as

in which m is the slope obtained from the derivative, m=23

and (x1,y1) is the point of tangency, (2,34). We then have that

Converting it to slope-intercept form, we have that

Example Question #232 : Writing Equations

Write the equation of the line (in slope-intercept form) normal to the curve at x=2 for the given function f(x).

Possible Answers:

None of the other answers. 

Correct answer:

Explanation:

The equation of the normal line is defined as the line that is perpendicular to the line tangent to the curve at the point of tangency, which occurs at x=2 in this case.

The line perpendicular to the tangent line will have a slope equal to the negative reciprocal of the slope of the tangent line.

If the slope of the tangent line is denoted by the variable n, the normal line will have a slope (m) in which

 

We begin by defining the point of tangency (x1,y1) and the slope of the tangent line, n. 

  ; 

  ; 

We then have that the slope of the normal line, m is

Utilizing the Point-Slope Formula y-y1=m(x-x1), we have that

Converting to Slope-Intercept form, we get that the slope of the normal line is

Example Question #1281 : Functions

Evaluate the third derivative of the following trigonometric function.

Possible Answers:

None of the other answers. 

Correct answer:

Explanation:

To evaluate higher order derivative of trigonometric functions like the tangent function, we must become familiar with all of the other derivation rules; in this case we will use the Chain Rule and the Product Rule. 

We begin with the identity that 

Since the first derivative has now turned into a composite function in the form

 where    and   

and      and  

we have that the second derivative, utilizing the Chain Rule, is

To obtain the third derivative, we must derive the second derivative via the Product Rule, since there is the multiplication of u=2[sec(x)]^2 and v=tan(x).

Recall that the Product Rule states that for a function, f(x)=uv:

As a result we have that

Example Question #52 : How To Write Equations

Find the derivative of the following multivariable equation. 

Possible Answers:

None of the other answers. 

Correct answer:

Explanation:

In order to solve for the derivative of an equation that is not written as a function of a single variable (x), but rather two variables (x and y), we must implement Implicit Differentiation. 

Implicit Differentiation states that when the derivative of a function in terms of one variable (in this case, y) is taken with respect to the other variable present (in this case,x), one must multiply that derived term, f'(y) by the by the derivative (y' or dy/dx). 

In other words, if we have a function in terms of y, we have that it's derivative with respect to x is 

In this case, we must derive both sides of the equation, so we begin with the left side f(x,y)=6xy. Since two terms are being multiplied, we must implement the product rule. We then have that

Then we look at the right side of the equation f(x,y)=x^2+y^2 and we have that

Putting together the left and the right side of the equations, we have that

Algebraically, we simplify this equation to

To isolate our derivative term (dy/dx), we divide the left term by (2y-6x) to get:

Learning Tools by Varsity Tutors