Page 10 - Trigonometry

Write this as,

sin ( ) [2 cos ( ) + 1] = 0
2 2

This becomes
1
cos ( ) = −
2 2
1 1
= cos −1 (− ) or = 2 cos −1 (− )
2 2 2
The keystrokes for this are,
C2q>z1R2$)=

This is now M, test the result with the original

equation,

sin( ) + sin ( ) = 0
2
The keystrokes are,
jM)+jMa2$)=

Proving the answer is correct. The calculator is very

useful for confirming you have the right answer.

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