cos(x) +sin(x)tan(x)=sec(x)
multiply by cos(x) on both sides
cos^2(x)+sin^2(x)=1
1=1
I believe they are probably asking you to prove the identity
2006-11-20 15:19:40
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answer #1
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answered by Greg G 5
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Cosx + Sinx * Tanx = Secx
cos x+sin^2 x/cos x=1/cos x multiply by cos x
cos^2 x+sin^ x=1
1=1
it is an identity
2006-11-20 15:43:26
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answer #2
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answered by yupchagee 7
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the question is to be taken as
prove that cosx+sinx*tanx= secx
cosx+sinx*tanx
= cosx+sinx*(sinx/cosx)
mutiplying each term by cos x
=(cosx*cosx+sinx*sinx)/cosx
=1/cosx
since cosx*cosx+sinx*sinx
=(cos^2x+sin^2x) = 1
and by definition
1/cosx = secx
2006-11-20 20:03:13
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answer #3
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answered by grandpa 4
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cos x +sinx *tan x =sec x
cos x +sin x *sin x/cos x = 1/ cos x
cos^2 x +sin^2 x =1
1=1
2006-11-20 15:21:35
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answer #4
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answered by ironduke8159 7
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cos(x) + sin(x)tan(x) = sec(x)
cos(x) + (sin(x) * sin(x)/cos(x)) = sec(x)
cos(x) + (sin(x)^2/cos(x)) = sec(x)
(cos(x)^2 + sin(x)^2)/(cos(x)) = sec(x)
cos(x)^2 + sin(x)^2 = 1
1/(cos(x)) = sec(x)
so
sec(x) = sec(x)
2006-11-20 15:34:25
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answer #5
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answered by Sherman81 6
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