Question

How do you solve the following, please show work.

If sin(theta)=0.3, find sin (theta+pi)

Answer 1

\[\sin(\theta+\pi)=\sin(\theta) \cos(\pi)+\sin(\pi) \cos(\theta)=?\]

Answer 2

\[\text{So I bet you you are having troubles with the } \cos(\theta) \text{ part } \]
Am I right?

Answer 3

We are given \[\sin(\theta)=\frac{3}{10}\]
Draw a right triangle giving measurement 10 to the hyp and measurement 3 to the opp

Answer 4

Use the Pythagorean thm to find the adj side :)

Answer 5

\[\text{Then boom you can find } \cos(\theta)\]

Answer 6

looking at the graph of sin(x) (or using the expansion of sin(a + b)) you can see that sin(x + pi) = -sin(x), just another way to approach it