### Trig Equations

Click the question to get the solutions, including videos.

March 2013

**8.1** Simplify as far as possible:

8.1

OR

**8.2** Simplify WITHOUT the use of a calculator:

8.2

OR

**8.3** Prove that

8.3

**8.4** Prove that for any angle θ :

8.4

**8.5** If x = cos20

^{0}, use QUESTION 8.4 to show that

8.5

March 2012

**11.1** If

determine the following in terms of p:

**11.1.1** sin 241°

11.1.1

**11.1.2** cos 61°

11.1.2

**11.1.3** cos 122°

11.1.3

**11.1.4** cos73° cos15° + sin73° sin15°

11.1.4

**11.2**

**11.2.1** Prove the identity:

11.2.1

**11.2.2** Determine a value of x in the interval [0° ; 180°] for which the identity is
not valid.

11.2.2

**11.3**

**11.3.1** Given: sin x = cos2x -1. Show that

11.3.1

**11.3.2** Determine the general solution of the equation:

sin x = cos 2x - 1.

11.3.2

OR

**11.4** Determine the value of:

tan1°×tan2°×tan3°×tan4°×... ×tan87°×tan88°×tan89°.

11.4

OR

----------------------------------