Q5 of 80 Page 295

If cot θ = 2, then let us determine the values of tan θ and sec θ and show that 1+ tan² θ = sec² θ.

Given, cotθ = 2

Need to show 1 + tan²θ = sec²θ

⇒ = 2

⇒ =

⇒ hypothesis² = perpindicular² + base²

= 1 + 2²

= 5

⇒ hypothesis = √5

⇒ =

⇒ 1 + tan²θ =

⇒ sec²θ =

∴ LHS = RHS

If in a right angled triangle ABC, ∠C=90°, DC = 21 unit and AB = 29 units, then let us find the values of sinA, cosA, sinB and cosB.

If cos then let us determine the values of all trigonometric ratio of the angle θ.

If cos θ = 0.6, then let us show that, (5 sin θ – 3 tan θ) = 0.

If cot then let us determine the values of cos A and cosec A and show that 1 + cot² A = cosec²A.

Questions · 80

23. Trigonometric Ratios and Trigonometric Identities

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If cot θ = 2, then let us determine the values of tan θ and sec θ and show that 1+ tan2 θ = sec2 θ.