cos 20 degree minus sin 20 degree / cos 20 degree + sin 20 degree is equals to tan 25degrees prove
Answers
Answered by
5
LHS:
cos20 degree-sin20 degree/cos20 degree+sin20 degree
dividing numerator andenominator by cos20degree we get:
=1-tan20degree/1+tan20degree
we know the value of tan45degree is 1 so
we get
=tan45degree-tan20degree/1+tan45degree×tan20degree
=tan(45degree-tan20degree)
=tan25degree. (proved)
cos20 degree-sin20 degree/cos20 degree+sin20 degree
dividing numerator andenominator by cos20degree we get:
=1-tan20degree/1+tan20degree
we know the value of tan45degree is 1 so
we get
=tan45degree-tan20degree/1+tan45degree×tan20degree
=tan(45degree-tan20degree)
=tan25degree. (proved)
rakhi28:
how tan45
the value of tan45deqree is 1
there is a formulae that i have used here is tan(x-y)=tanx-tany/1-tanxtany
Similar questions