Question

1. find A if
sin(2A+45)=cos(30-A)...
2.. tan4A+tan2A=sec4A-sec2A.....prove it

Answer 1

(1) sin(2A + 45) = cos(30-A)

=> sin(2A+45) = sin{90-(30-A)

=> 2A + 45 = 90 - 30 + A

=> A = 60 - 45

=> A = 15




---------(2)


tan⁴A + tan²A

=> tan²A(tan²A + 1)

=> (sec²A - 1) sec²A

=> SEC⁴A - sec²A