pls answer this one for me sin^2 x/ cos ^2 x = sec x-cos x
2007-02-21 21:12:45 · 5 answers · asked by -bEtTy- B 1 in Science & Mathematics ➔ Mathematics
This identity is wrong.
You can verify this by putting any value of x.
Say if you put x= 45,then
sin^2 45 = 1/2
cos^2 45 = 1/2
sec 45 = sqrt(2)
cos 45 = 1/sqrt(2)
Instead of this the actual identity is
sin^2 x/cos x = sec x-cos x.
2007-02-21 21:22:31 · answer #1 · answered by wadi 2 · 0⤊ 0⤋
This is true only for x = 41.191deg, 126.424deg.
Therefore, it is not an identity.
However, the following are true:
(sin x + cos x )^2 = 1 + sin 2x
sec x - cos x = tan x sin x
2007-02-22 06:02:41 · answer #2 · answered by math freak 3 · 0⤊ 0⤋
This is not an identity. Counter-example with x = 30 deg:
LHS = (1/4)/(3/4) = 1/3
RHS = (2sqrt3)/3 - (sqrt3)/2 = (sqrt3) / 6
2007-02-22 05:26:32 · answer #3 · answered by Anonymous · 0⤊ 0⤋
Your Equation is wrong.
It should be
Sin^2x / Cos^2x = Sec^2x-1
2007-02-22 05:30:59 · answer #4 · answered by GS 3 · 0⤊ 0⤋
Life is difficult enough without having to guess what the question should be!!
2007-02-22 05:54:11 · answer #5 · answered by Como 7 · 0⤊ 1⤋