Question 1113683
<pre>
7sin²x - 14sinx + 2 = -5

Get 0 on the right by adding 5 to both sides:

7sin²x - 14sinx + 7 = 0

Since every term is divisible by 7, we divide through by 7:

sin²x - 2sinx + 1 = 0

Factor as a trinomial:

(sinx-1)(sinx-1) = 0

(sinx-1)² = 0

sinx-1 = 0

sinx = 1

x = <font face="symbol">p</font>/2 + 2<font face="symbol">p</font>&#8729;n

Edwin</pre>