How to find the equation of a curve - GRE Quantitative Reasoning
Card 0 of 3
What is the slope of the line whose equation is 
?
What is the slope of the line whose equation is
Solve for 
so that the equation resembles the 
form. This equation becomes 
. In this form, the 
is the slope, which is 
.
Solve for
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Which of the following equations has a 
-intercept of 
?
Which of the following equations has a
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 
:
To find the
Substitute in
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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 
?
If
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 
.
If
If its
The slope of this line is
Therefore, any line perpendicular to this line must have a slope equal to the negative reciprocal, which is
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