Saturday, March 16, 2013

Q13/027) solve for ø sin^2ø+cos^2ø+tan^2ø+sec^2ø+ csc^2ø+cot^ø=7

sin^2ø+cos^2ø+tan^2ø+sec^2ø+ csc^2ø+cot^ø
= 1 + tan^2ø + 1 + tan^2ø + 1 + cot^ø + cot^ø = 7 ( as sin^2ø+cos^2ø = 1, sec^2ø = tan ^2ø + 1 , csc^2ø = cot ^2ø + 1)
= 3 + 2 ( tan ^2 ø + cot ^2ø) = 7
or ( tan ^2 ø + cot ^2ø) = 2
or ( tan ^2 ø + cot ^2ø) - 2 tan ø cot2ø = 0
or ( tan ø - cot ø)^ 2 = 0

or ( tan ø = cot ø) = 1 or -1 so ø = pi/4 is a solution other solutions are 3pi/4, 5pi/4, 7pi/4

No comments: