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Q) For acute angles A and B, if sec (2 A – B) = √2 and cosec (A + B) = 2 then find the values of A and B. (Q 22 A – 30/5/2 – CBSE 2026 Question Paper) Ans: Step 1: Given that sec (2 A – B) = √2 ∵ we know […]
trigonometry
Q) Evaluate: . (Q 22 B – 30/5/2 – CBSE 2026 Question Paper) Ans: We know that cos 30Â 0 = cot 60Â 0 = and tan 30Â 0 = Given expression is: By substituting these values, we get: = = Â = = = = Therefore, the value of the given expression is . Please press “Heart”
Q) Prove that: (1 + cot θ – cosec θ) (1 + tan θ + sec θ) = 2. (Q 31 – 30/5/2 – CBSE 2026 Question Paper) Ans: Step 1: Let’s start from LHS: LHS = (1 + cot θ – cosec θ) (1 + tan θ + sec θ) = = = Step
31. Prove that: (1 + cot θ – cosec θ) (1 + tan θ + sec θ) = 2 Read More »
Q) Prove that : √[(1 + sin A)/(1−sin A)] = sec A + tan A. (Q 25 A – 30/4/2 – CBSE 2026 Question Paper) Ans: Step 1: Let’s start solving LHS: LHS = Here we have (1 – sin A) in the denominator. To nullify this, we need to multiply & divide by its
25 a. Prove that : √[(1 + sin A)/(1−sin A)] = sec A + tan A. Read More »
Q) Evaluate : (3 cos 2 30 – 6 cosec 2 30) / tan 2 60. (Q 25 B – 30/4/2 – CBSE 2026 Question Paper) Ans: Step 1:Given expression is: It can also be expressed as: Step 2: We know that the value of cos 30 0 = , cosec 30 0 = 2 and tan 60 0 = √3
25 b. Evaluate : (3 cos2 30◦−6 csc2 30◦)/tan2 60◦ Read More »
Q) Prove that: (Q 30 – 30/4/2 – CBSE 2026 Question Paper) Ans: [Note: solved in two methods: please choose whichever you find easier] Method 1: Step 1: Let’s start from LHS and simplify it: LHS = = = = = = ∵ by trigonometric identity, sin 2 θ + cos 2 θ = 1 ∴ LHS
30. Prove that: 1 /(sec x − tan x) − 1/cos x = 1/cos x – 1 / (sec x + tan x) Read More »
Q) If sin θ + cos θ = √3, then prove that tan θ + cot θ = 1 (Q 29 A – 30/3/3 – CBSE 2026 Question Paper) Ans: Step 1: Its given that sin θ + cos θ = √3 Squaring on both sides, we get ∴ (sin θ + cos θ) 2 =
29 a. If sin θ + cos θ = √3, then prove that tan θ + cot θ = 1 Read More »
Q) Prove that: (sin A + sec A)2 + (cos A + cosec A)2 = (1 + sec A cosec A)2. (Q 29 B – 30/3/3 – CBSE 2026 Question Paper) Ans: Let’s start from LHS: ∴ LHS = (sin A + sec A) 2 + (cos A + cosec A) 2 By algebraic identity,
29 b. Prove that: (sin A + sec A) ^ 2 + (cos A + cosec A) ^ 2 = (1 + sec A cosec A) ^ 2 Read More »
Q) If tan θ =24/7, then find the value of sin θ + cos θ. (Q 22 A – 30/1/3 – CBSE 2026 Question Paper) Ans: Step 1: We know that in a right angled triangle, tan θ is given by: Since we are given that tan θ = ∴ We can assume that Opposite
22 a. If tan θ =24/7, then find the value of sin θ + cos θ. Read More »
Q) If cot θ =7/8, then find the value of (1+sin θ)(1−sin θ)/(1+cos θ)(1−cos θ). (Q 22 B – 30/1/3 – CBSE 2026 Question Paper) Ans: Step 1: Let’s first simiplify the given expression: = ………… (i) Step 2: From Trigonometric identity, we know that sin 2 θ + cos 2 θ = 1 ∴ 1