Kx=3
x=0,4
k*0,4=3
k=3:0,4
<u>k=7,5</u>
kx=-1
7,5x=-1
x=-1:7,5
x=-10/75
<u>x= -2/15</u>
Решение
<span>Sin7x+sin6x+sin5x = (sin7x + sin5x) + sin6x =
</span>= 2*[sin(7x + 5x)/2 * cos(7x - 5x)/2] + sin6x =
= 2*sin6x * cosx + sin6x = sin6x*(2cosx + 1)
<u>2x </u> : <u> 3 </u>* <u> 9 </u> : <u> х </u> = (<u>2x </u>* <u>2x)</u> * ( <u> 9 </u> * <u>2y)</u> =
3 2х 4ху 2у 3 3 4xy x
=<u> 4x² </u> * <u> 9 </u>= 2
9 2x²
2×37=74
74×29=2146
1369-2146=-777
-777+841=64
√64=8