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प्रश्न
If \[\tan \theta = \frac{3}{4}\] then cos2 θ − sin2 θ =
पर्याय
\[\frac{7}{25}\]
1
\[\frac{- 7}{25}\]
\[\frac{4}{25}\]
उत्तर
Given that:` tan θ=3/4`
Since ` tan x= "Perpendicular"/"Base"`
⇒` "Perpendicular"=3`
⇒`"Base"=4`
⇒ `"Hypotenuse"=sert(9+16)`
⇒` "Hypotenuse"=5`
We know that sin θ= `"Prependicular"/"Hypotenuse" and cos θ= "Base"/"Hypotenuse" `
We find:
`cos^2θ-sin ^2 θ`
=`(4/5)^2-(3/5)^2`
=`16/25-9/25`
= `7/25`
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