  ### Home > INT3 > Chapter 10 > Lesson 10.3.3 > Problem10-188

10-188.

Solve each equation for $0^\circ\leθ<360^\circ$. You may need your calculator, but remember that your calculator only gives one answer. Most of these problems have more than one answer. Think about all four quadrants of a graph.

1. $\operatorname { sin } ( \theta ) = 0.5$

Where is the $\text{sin}θ = 0.5$? Remember sin is the $y$-value. What would $θ$ be at those places?

$θ = 30^\circ$ or $150^\circ$

1. $\operatorname { cos } ( \theta ) = - 0.5$

Where is the $\text{cos}θ = −0.5$? Remember cos is the $x$-value. What would $θ$ be at those places?

1. $4 \operatorname { tan } ( \theta ) - 4 = 0$

Solve for the $\text{tan}θ$. Draw a unit circle. Where is the $\text{tan}θ$ of that value?

1. $3 \operatorname { sin } ^ { 2 } ( \theta ) = 1$

Use your calculator to get one of the values. Then use symmetry to get the other 3 values. There are 4 values because when you take the square root of both sides the answer would be plus or minus!