All Precalculus Resources
Example Questions
Example Question #2 : Express A Vector In Polar Form
Write the vector in polar form, .
It will be helpful to first draw the vector so we can see what quadrant the angle is in:
Since the vector is pointing up and to the right, it is in the first quadrant. To determine the angle, set up a trig equation with tangent, since the component 5 is opposite and the component 4 is adjacent to the angle we are looking for:
to solve for theta, take the inverse tangent of both sides:
Now we have the direction, and we can solve for the magnitude using Pythagorean Theorem:
take the square root of both sides
The vector in polar form is
Example Question #31 : Algebraic Vectors And Parametric Equations
Express the following vector in component form:
None of the other answers
When separating a vector into its component form, we are essentially creating a right triangle with the vector being the hypotenuse.
Therefore, we can find each component using the cos (for the x component) and sin (for the y component) functions:
We can now represent these two components together using the denotations i (for the x component) and j (for the y component).
Example Question #2 : Express A Vector In Component Form
Find , then find its magnitude. and are both vectors.
In vector addition, you simply add each component of the vectors to each other.
x component: .
y component: .
z component: .
The new vector is
.
To find the magnitude we use the formula,
Thus its magnitude is 5.
Example Question #1 : Express A Vector In Component Form
Find the component form of the vector with
initial point
and
terminal point .
To find the vector in component form given the initial and terminal points, simply subtract the initial point from the terminal point.
Example Question #2 : Express A Vector In Component Form
Find the component form of the vector with
initial point
and
terminal point
To find the vector in component form given the initial and terminal points, simply subtract the initial point from the terminal point.
Example Question #32 : Algebraic Vectors And Parametric Equations
A bird flies 15 mph up at an angle of 45 degrees to the horizontal. What is the bird's velocity in component form?
Write the formula to find both the x and y-components of a vector.
Substitute the value of velocity and theta into the equations.
The vector is:
Example Question #1 : Express A Vector In Component Form
Write this vector in component form:
In order to find the horizontal component, set up an equation involving cosine with 7 as the hypotenuse, since the side in the implied triangle that represents the horizontal component is adjacent to the 22-degree angle:
First, find the cosine of 22, then multiply by 7
To find the vertical component, set up an equation involving sine, since the side in the implied triangle that represents the vertical component is opposite the 22-degree angle:
First, find the sine of 22, then multiply by 7
We are almost done, but we need to make a small adjustment. The picture indicates that the vector points up and to the left, so the horizontal component, 6.49, should be negative:
Example Question #31 : Algebraic Vectors And Parametric Equations
Write a vector equation describing the line passing through P1 (1, 4) and parallel to the vector = (3, 4).
First, draw the vector = (3, 4); this is represented in red below. Then, plot the point P1 (1, 4), and draw a line (represented in blue) through it that is parallel to the vector .
We must find the equation of line . For any point P2 (x, y) on , . Since is on line and is parallel to , for some value of t. By substitution, we have . Therefore, the equation is a vector equation describing all of the points (x, y) on line parallel to through P1 (1, 4).
Example Question #1 : Parametric Equations
True or false: A line through P1 (x1, y1) that is parallel to the vector is defined by the set of points such that for some real number t. Therefore, .
False
True
True
This is true. The independent variable in this equation is called a parameter.
Example Question #2 : Parametric Equations
Find the parametric equations for a line parallel to and passing through the point (0, 5).
x = 3
y = 2 + 5t
x = 3t
y = 5 + 2t
x = 3 + 2t
y = 5t
x = 5t
y = 3 + 2t
x = 3t
y = 5 + 2t
A line through a point (x1,y1) that is parallel to the vector = (a1, a2) has the following parametric equations, where t is any real number.
Using the given vector and point, we get the following:
x = 3t
y = 5 + 2t
Each value of t creates a distinct (x, y) ordered pair. You can think of these points as representing positions of an object, and of t as representing time in seconds. Evaluating the parametric equations for a value of t gives us the coordinates of the position of the object after t seconds have passed.
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