मराठी

Without Using Trigonometric Identity , Show that : Sec 70 ∘ Sin 20 ∘ − Cos 20 ∘ Cos E C 70 ∘ = 0 - Mathematics

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प्रश्न

Without using trigonometric identity , show that :

`sec70^circ sin20^circ - cos20^circ cosec70^circ = 0`

बेरीज

उत्तर

`sec70^circ sin20^circ - cos20^circ cosec70^circ = 0`

Consider `sec70^circ sin20^circ - cos20^circ cosec70^circ`

⇒ `sec(90^circ - 20^circ)sin20^circ - cos20^circ . cosec(90^circ - 20^circ)`

⇒ `cosec20^circ sin20^circ - cos20^circ sec20^circ`

⇒ `1/sin20^circ   . sin20^circ - cos20^circ  . 1/cos20^circ`

⇒ 1 - 1 = 0

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पाठ 21: Trigonometric Identities - Exercise 21.3

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फ्रँक Mathematics - Part 2 [English] Class 10 ICSE
पाठ 21 Trigonometric Identities
Exercise 21.3 | Q 3.05
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