What are the coordinates of the image of point (−1, 5) after a counterclockwise rotation of 90º about the origin?

Step-by-step explanation:

We have been given the coordinates of a point and we are asked to find the coordinates of he point after a counterclockwise rotation of 90º about the origin.  

We know that after rotating a point 90 degree counter-clockwise about the origin, the x and y-coordinates changes places with each other and x-coordinate of new point becomes the negative of y-coordinate.

Applying the rotation rule the coordinates of new point would be:

Therefore, the required coordinates of the given point after a counterclockwise rotation of 90º about the origin would be .

x² + 3x + 7 = 0       [ax² + bx + c]

a = 1

b = 3

c = 7

quadratic formula:

    (+/- is this ±)

plug in the numbers into the variables

your answer is a