GRE Math : How to find the equation of a curve

Study concepts, example questions & explanations for GRE Math

varsity tutors app store varsity tutors android store

Example Questions

Example Question #3 : X And Y Intercept

What is the slope of the line whose equation is \dpi{100} \small 8x+12y=20?

Possible Answers:

\dpi{100} \small \frac{2}{3}

\dpi{100} \small -\frac{3}{2}

\dpi{100} \small 2

\dpi{100} \small \frac{3}{2}

\dpi{100} \small -\frac{2}{3}

Correct answer:

\dpi{100} \small -\frac{2}{3}

Explanation:

Solve for \dpi{100} \small y so that the equation resembles the \dpi{100} \small y=mx+b form. This equation becomes \dpi{100} \small -\frac{2}{3}x+\frac{5}{3}. In this form, the \dpi{100} \small m is the slope, which is \dpi{100} \small -\frac{2}{3}.

Example Question #4 : X And Y Intercept

Which of the following equations has a -intercept of ?

Possible Answers:

Correct answer:

Explanation:

To find the -intercept, you need to find the value of the equation where .  The easiest way to do this is to substitute in  for your value of  and see where you get  for .  If you do this for each of your equations proposed as potential answers, you find that  is the answer.

Substitute in  for :

Example Question #5 : X And Y Intercept

If  is a line that has a -intercept of  and an -intercept of , which of the following is the equation of a line that is perpendicular to ?

Possible Answers:

Correct answer:

Explanation:

If  has a -intercept of , then it must pass through the point .

If its -intercept is , then it must through the point .

The slope of this line is .

Therefore, any line perpendicular to this line must have a slope equal to the negative reciprocal, which is . Only  has a slope of .

Learning Tools by Varsity Tutors

Incompatible Browser

Please upgrade or download one of the following browsers to use Instant Tutoring: