Question

If (a,b) is a point on the terminal side of angle t in standard position, then cos(t) equals:

Answer 1

plot the point. (for example, assume (a,b) is in the first quadrant)
label the sides of a triangle with hypotenuse from (0,0) to (a,b)
the sides should have length a for the x-axis, length b for the vertical leg
use pythagoras to find the length of the hypotenuse
(or the distance formula between the points (0,0) and (a,b) )
finally, write down the cosine (SOH CAH TOA )
Cosine = adjacent / hypotenuse