trigonometric equations 1

More practice and directions are in the attatched file.

Practice Problem #1) 16 Sinx – 4 = 0; x [0,2Ï€]

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 2Ï€/3 and 4Ï€/3

Answer = 1200 and 2400

Practice Problem #2) 16 Sinx – 4 = 0; x[0,2Ï€]