find all solution to the equation 3 cos(x+4)=1. in the interval of 0<x<2pi

This is what I got: arccos (1/3)+4 but I cant figure the rest out

Solve the following equation in the interval [0, 2pi]. (sin(t))^2=1/2. Give the answer as a multiple of pi.

1 answer

Your Algebra I is missing

3cos(x+4) = 1
cos(x+4) = 1/3
x+4 = arccos(1/3)
x = arccos(1/3) - 4 = 1.231
also, 2π-1.231 = 5.052

sin^2(t) = 1/2
sint = ±1/√2
since sin π/4 = 1/√2
t = all odd multiples of π/4