All Precalculus Resources
Example Questions
Example Question #4 : Solve Nonlinear Systems Of Equations
Solve the following system:
Our first step is to solve the bottom equation for :
so we can substitute it into the top equation:
Now we can plug in our y-values into the bottom equation to find our x-values:
Remember we cannot take a square root of a negative number without getting an imaginary number. As such, we'll just focus on the values.
Our solution is then:
Example Question #5 : Solve Nonlinear Systems Of Equations
Solve the following system for :
The first step is to solve the bottom equation for :
since our question specifies for we just focus on
We now substitute this equation into the top equation:
we can now plug in our x-values into the bottom equation to find our y-values:
The solutions are then:
Example Question #6 : Solve Nonlinear Systems Of Equations
Solve the following system:
We can solve this equation by using substitution since the bottom equation is already solved for . Substituting the bottom equation into the top we get:
We then solve the equation for our values:
Finally, we substitute our values into the bottom equation to get our values:
Our different solutions are then:
Example Question #821 : Pre Calculus
Solve the following system:
We can substitute the top equation into the bottom:
and solve for values:
Now that we have our values we can plug it into the top equation and find our values
So, our values are
Example Question #1 : Solving Polynomial And Rational Inequalities
What is the solution to the following inequality?
First, we must solve for the roots of the cubic polynomial equation.
We obtain that the roots are .
Now there are four regions created by these numbers:
- . In this region, the values of the polynomial are negative (i.e.plug in and you obtain
- . In this region, the values of the polynomial are positive (when , polynomial evaluates to )
- . In this region the polynomial switches again to negative.
- . In this region the values of the polynomial are positive
Hence the two regions we want are and .
Example Question #1 : Solve And Graph Rational Inequalities
Solve the inequality.
First, subtract from both sides so you get
.
Then find the common denominator and simplify
.
Next, factor out the numerator
and set each of the three factor equal to zero and solve for .
The solutions are
.
Now plug in values between , , , and into the inequality and observe if the conditions of the inequality are met.
Note that . They are met in the interval and .
Thus, the solution to the inequality is
.
Example Question #1 : Solving Polynomial And Rational Inequalities
Solve and graph:
1) Multiply both sides of the equation by the common denominator of the fractions:
2) Simplify:
3) For standard notation, and the fact that inequalities can be read backwards:
For interval notation:
4) Graph:
Example Question #822 : Pre Calculus
Solve and graph:
Graph the rational expression,
1) Because and a divide by is undefined in the real number system, there is a vertical asymptote where .
2) As , , and as , .
3) As , , and as , .
4) The funtion y is exists over the allowed x-intervals:
One approach for solving the inequality:
For
1) Determine where over the x-values or .
2) for the intervals or .
3) Then the solution is .
Another approach for solving the inequality:
1) Write as , then determine the x-values that cause to be true:
2) is true for or .
3) Then the solution is .
Example Question #2 : Solving Polynomial And Rational Inequalities
Which of the following best describes the statement:
The undefined points of rational functions are vertical asymptotes.
The statement is always false
The statement is true in some cases and false in others
The statement is always true
The statement is always true
When solving for a point where the function will be undefined, you set the denominator equal to zero and solve for . This creates a vertical asymptote because when the denominator equals zero the function is undefined and we are solving for . Say for example a function is undefined at . So at all values of where this function is undefined creating a vertical asymptote.
Example Question #5 : Solve And Graph Rational Inequalities
We begin by finding the zeros of the equation using the numerator.
So we know that the function will equal zero when . If we just look at the numerator of the function, then this graph would be a parabola with its point at . Now we will solve for the points where the function is undefined by setting the denominator equal to zero and solving for .
And so the function is undefined at . If we make a table to solve for some of the points of the graph:
And if we graph these points we see something like below (which is our answer). Note that the dotted blue line is the vertical asymptote at .
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