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Question
tan2θ – sin2θ = tan2θ × sin2θ. For proof of this complete the activity given below.
Activity:
L.H.S. = `square`
= `square (1 - (sin^2θ)/(tan^2θ))`
= `tan^2θ (1 - square/((sin^2θ)/(cos^2θ)))`
= `tan^2θ (1 - (sin^2θ)/1 xx (cos^2θ)/square)`
= `tan^2θ (1 - square)`
= `tan^2θ xx square` ...[1 – cos2θ = sin2θ]
= R.H.S.
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Solution
L.H.S. = \[\boxed{\text{tan}^2θ - \text{sin}^2θ}\]
= \[\boxed{\text{tan}^2θ} \left(1 - \frac{\text{sin}^2θ}{\text{tan}^2θ}\right)\]
= \[\tan^2\theta\left(1-\frac{\boxed{\sin^2\theta}}{\frac{\sin^2\theta}{\cos^2\theta}}\right)\]
= \[\tan^{2}\theta\left(1-\frac{\sin^{2}\theta}{1}\times\frac{\cos^{2}\theta}{\boxed{\sin^{2}\theta}}\right)\]
= \[\text{tan}^2θ \left(1 - \boxed{\text{cos}^2θ}\right)\]
= \[\text{tan}^2θ × \boxed{\text{sin}^2θ}\] ...[1 – cos2θ = sin2θ]
= R.H.S.
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L.H.S. = `square`
= `square/(sinθ) + (sinθ)/(cosθ)`
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= `1/(sinθ.cosθ)` ...`[cos^2θ + sin^2θ = square]`
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= `square`
= R.H.S.
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