Question

what basic trigonometric identity would you use to verify that tan x cos x= sin x?
a. cos x=1/sec x
b. sin s=1/csc x
c. cos^2x + sin^2x=1
d. tan x = sin x/ cos x

Answer 1

D

Answer 2

Converting everything to sines and cosines will usually work.
So, tan(x)cos(x) = sin(x)
(sin(x)/cos(x))cos(x) = sin(x)
sin(x) = sin(x)