Question

cos² 45 -sin² 15
pls answer this question​

Answer 1

Answer:

1-√3/4

Step-by-step explanation:

cos²45-sin²15=(1/√2)²-(√3-1)²/(2√2)²

                      =1/2-(3-2√3+1)/8

                       =1/2-(2-2√3)/8

                       =1/2-[2(1-√3)]/8

                        =1/2-(1-√3)/4

                         =2-1-√3/4

                          =1-√3/4

Answer 2

Answer:

√3/4

Step-by-step explanation:

(1/√2)²-(√3-1)²/(2√2)²=1/2-(3+1-2√3)/8

=4-4+2√3/8

=2√3/8=√3/4