Question

4-2 ctg^2x*sin^2x,если sinx=-0,2

Answer 1

4 - 2 Ctg² x * Sin² x = 4 - 2 * Cos²x/Sin²x  * Sin²x = 4 - 2Cos²x = 
=4 - 2(1 - Sin²x) = 4 - 2 + 2Sin²x = 2 + 2*0,04= 2 + 0,08 = 2,08

Answer 2

4-2*ctg²x*sin²x=2+2*sin²x+2*cos²x-2*sin²x*cos²x/sin²x=
=2+2*sin²x+2*cos²x-2*cos²x=2+sin²x=2+2*(-0,2)²=2+2*0,04=2,08.