1) prove cos3A=4cos^3A-3cosA
2) prove 4cos2AsinAcosA =sin4A
6. find real number of x and y such that (2x-j3y)-(1+j5)x=3+j2
ans y=-17/3,x=3
Can anyone provide me the explainations for the above question. i tried hard but i am lost. Help needed.
1) prove cos3A=4cos^3A-3cosA
2) prove 4cos2AsinAcosA =sin4A
6. find real number of x and y such that (2x-j3y)-(1+j5)x=3+j2
ans y=-17/3,x=3
Can anyone provide me the explainations for the above question. i tried hard but i am lost. Help needed.
Hello, watsonmath!
You need these identities:
. .
. .
. .
1) Prove: .
We have: .
. . . . . . . . . . . .
. . . . . . . . . . . .
. . . . . . . . . . . .
. . . . . . . . . . . .
. . . . . . . . . . . .
. . . . . . . . . . . .
2) Prove: .
We have: .
. . . . . .
. . . . . .