Ex 1B: Solving a Trigonometric Equation with a Multiple Angle Using Substitution

This video solving a trig equation with a multiple angle using substitution. Reference triangles are used.

[nrowe]

I think it would've been less work to solve for cos(4x) after dividing the 4 into 2 so that cos(4x)=1/2 ---> 4x=(pi/3 + 2pi) And 4x= (5pi/3 + 2pi) ----> x= (pi/12 + pi/2) and x= (5pi/12 + pi/2) that way you get rid of the 4 in 4x at the beginning and dont have to constantly multiply everything by 1/4 the whole problem