West Texas A&M UniversityTrigonometric Equations Questions Response
More practice and directions are in the attatched file.
Practice Problem #1) 16 Sinx – 4 = 0; x [0,2π]
Explanation #1
Step 1) 4(cosx+1) = 2
4 Cosx + 4 = 2
4 Cosx = 2 – 4
4 Cosx = -2
Cosx = -2/4
Cosx = -1/2
Step 2) Cos is negative and as a result found in Quadrant II and Quadrant III.
A cos value of -1/2 is a reference angle of 600.
This is considered the reference angle of 600 quadrants II and III.
x = 1200 and 2400 or 2π/3 and 4π/3
Answer = 1200 and 2400
Practice Problem #2) 16 Sinx – 4 = 0; x[0,2π]