Algebra 2 could someone help me?

Question

If tan x=3/4, and 0<x<π/2, what is cos⁡(x−3π/2)?

Answer 1

cos(x-3pi/2) = 0.6

tanx = 3/4

x = arctan.75 = about 36.87 degrees

use a calculator with inverse trig functions

cos(x-3pi/2) = cos(x -270) = cos(36.87 -270) = cos(90-36.87) = cos53.13 = .6