Question

Given that sin*=5\17o<\*< 90 evaluate cos*-2sin*\2tan*

Answer 1

sin𝜃 = 5/17 and 𝜃 is in quadrant I
make a sketch of your triangle and using Pythagoras, ...
x^2 + 5^2 = 17^2
x= √264

now that you have x, y, and r, you can find any of the 6 trig ratios

btw, use / to show division
also, I have suspicion that you mean
(cos𝜃 - 2sin𝜃)/2tan𝜃

you decide before calculating