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Prove the identity (sin θ + cos θ)(tan θ + cot θ) = sec θ + cosec θ. - Mathematics

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प्रश्न

Prove the identity (sin θ + cos θ)(tan θ + cot θ) = sec θ + cosec θ.

योग

उत्तर

L.H.S. = (sin θ + cos θ)(tan θ + cot θ)

= `(sin theta + cos theta)(sin theta/cos theta + costheta/sin theta)`

= `(sin theta + cos theta)((sin^2 theta + cos^2 theta)/(costhetasin theta))`

= `(sintheta+costheta)xx1/(sinthetacostheta)`   ...[∵ sin2θ + cos2θ = 1]

= `(sin theta + cos theta)/(cos theta sin theta)`

= `sin theta/(cos thetasin theta) + cos theta/(cos theta sin theta)`

= `1/cos theta + 1/sin theta`

= `sec theta + cosec  theta`

= R.H.S

Hence proved.

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  क्या इस प्रश्न या उत्तर में कोई त्रुटि है?
अध्याय 21: Trigonometrical Identities - Exercise 21 (E) [पृष्ठ ३३३]

APPEARS IN

सेलिना Mathematics [English] Class 10 ICSE
अध्याय 21 Trigonometrical Identities
Exercise 21 (E) | Q 15 | पृष्ठ ३३३
आईसीएसई Mathematics [English] Class 10
अध्याय 18 Trigonometry
Exercise 2 | Q 52

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