find the cosine of the angle formed with the coordinates (-6, 7) located in standard position
Plot the point (-6,7)
Draw the radius vector, r, from the origin (0,0) to the point (-6,7).
Indicate the angle. I'll call it
.
Draw a vertical line perpendicular down to the x-axis, and
label it
.
Draw a horizontal line from the origin to the bottom of
that line, completing a right triangle. Label it
Now we find the length of
by the Pythagorean theorem:
So we put
for
:
Now since
Edwin