If a + B = 90° then cosa + cos2B equals to:
Answers
Answered by
2
a=30 b=30
cosa + cos 2 b
cos 30+ cos 2(30)
cos 30+cos 60
cos a+b =90
a+b =90
cosa+cos2B is equal to the a+b=90
chdileep70:
thank you!
wc
but the answer is not correct
because the question is defferent. to the answer
the answer is 1
Answered by
2
cosa + cos2B
=2cos(a+2B)/2 ×cos(a-2B)/2
=2cos(90+B)/2×cos(90-3B)/2
=2cos(a+2B)/2 ×cos(a-2B)/2
=2cos(90+B)/2×cos(90-3B)/2
tell clear
ok
Similar questions