All GMAT Math Resources
Example Questions
Example Question #11 : Coordinate Geometry
A line segment has its midpoint at and an endpoint at . What are the coordinates of the other endpoint?
Because we are given the midpoint and one of the endpoints, we know the x coordinate of the other endpoint will be the same distance away from the midpoint in the x direction, and the y coordinate of the other endpoint will be the same distance away from the midpoint in the y direction. Given two endpoints of the form:
The midpoint of these two endpoints has the coordinates:
Plugging in values for the given midpoint and one of the endpoints, which we can see is because it lies to the right of the midpoint, we can solve for the other endpoint as follows:
So the other endpoint has the coordinates
Example Question #2 : Calculating The Endpoints Of A Line Segment
Consider segment with endpoint at . If the midpoint of can be found at , what are the coordinates of point ?
Recall midpoint formula:
In this case we have (x'y') and one of our other (x,y) points.
Plug and chug:
If you make this into two equations and solve you get the following.
Example Question #11 : Coordinate Geometry
A line segement on the coordinate plane has endpoints and . Which of the following expressions is equal to the length of the segment?
Apply the distance formula, setting
:
Example Question #12 : Coordinate Geometry
What is distance between and ?
Example Question #13 : Coordinate Geometry
What is the distance between the points and ?
Let's plug our coordinates into the distance formula.
Example Question #14 : Coordinate Geometry
What is the distance between the points and ?
We need to use the distance formula to calculate the distance between these two points.
Example Question #15 : Coordinate Geometry
Consider segment which passes through the points and .
Find the length of segment .
This question requires careful application of distance formula, which is really a modified form of Pythagorean theorem.
Plug in everthing and solve:
So our answer is 156.6
Example Question #16 : Coordinate Geometry
What is the length of a line segment that starts at the point and ends at the point ?
Using the distance formula for the length of a line between two points, we can plug in the given values and determine the length of the line segment by calculating the distance between the two points:
Example Question #1 : Calculating The Equation Of A Tangent Line
Determine the equation of the line tangent to the curve at the point ?
To find the equation of a line tangent to a curve at a certain point, we first need to find the slope of the curve at that point. To find the slope of a function at any point, we need its derivative:
Now we can plug in the x value of the given point to find the slope of the function, and therefore the slope of tangent line, at that point:
Now that we have our slope, we can simply plug this value in with the given point to solve for the y intercept of the tangent line:
We have calculated the slope of the tangent line and its y intercept, so the equation for the line tangent to the curve at the point in standard form is:
Example Question #855 : Gmat Quantitative Reasoning
Determine the equation of the line tangent to the following curve at the point .
First we find the slope of the tangent line by taking the derivative of the function and plugging in the -value of the point where we want to know the slope:
Now that we know the slope of the tangent line, we can plug it into the equation for a line along with the coordinates of the given point in order to calculate the -intercept:
We now have and , so we can write the equation of the tangent line: