Question

sin^4(15) + cos^4(15) =

Answer 1

sin^4(15)+cos^4(15)=(sin^2(15)+cos^2(15))^2-2*sin^2(15)*cos^2(15)

Answer 2

7\8

Answer 3

sin^2(15)+cos^2(15)=1 as sin^2(x)+cos^2(x)=1

Answer 4

and 2sinx*cosx=sin2x

Answer 5

could you explain it by steps and which methods did you use

Answer 6

that one makes me feel discomfort with the question

Answer 7

sin^4(15)+cos^4(15)=(1)^2-2*sin^2(15)*cos^2(15)
=1-(1/2)2*2*sin^2(15)*cos^2(15)
=1-(1/2)*(2*sin15*cos15)^2
=1-(1/2)(sin(2*15))^2
=1-(1/2)sin^2(30)
=1-(1/2)*(1/2)^2
=1-1/2*1/4
=1-1/8
=7/8

Answer 8

it is in form of sin^4x+cos^4x

Answer 9

thank you very much)))

Answer 10

so try to convert in sin^2x and cos^2x