Q) If the sum of first 7 terms of an A.P. is 49 and that of first 17 terms is 289, find the sum of its first 20 terms. Ans: Let’s consider the first term be A and the common difference be D. Step 1: We know that sum of first n terms of an A.P. […]
If the sum of first 7 terms of an A.P. is 49 and that of first 17 terms is 289 Read More »
Q) Prove that Ans: Let’s start from LHS: LHS = = We know that sin2 θ + cos2 θ = 1 By substituting this value in the above equation, we get: LHS = = = = = = = Hence Proved ! Please do press “Heart” button if you liked the solution.
Prove that (sin θ – 2 sin3 θ) / (2 cos3 θ – cos θ) = tan θ Read More »
Q) Vocational training complements traditional education by providing practical skills and hands-on experience. While education equips individuals with a broad knowledge base, vocational training focuses on job-specific skills, enhancing employability thus making the student self reliant. Keeping this in view, a teacher made the following table giving the frequency distribution of students/adults undergoing vocational training
Vocational training complements traditional education by providing practical skills Read More »
Q) A stable owner has four horses. He usually tie these horses with 7 m long rope to pegs at each corner of a square shaped grass field of 20 m length, to graze in his farm. But tying with rope sometimes results in injuries to his horses, so he decided to build fence around the
A stable owner has four horses. He usually tie these horses with 7 m long rope to pegs Read More »
Q) Prove that , if . Ans: Let’s start from LHS: LHS = = = = = = ∵ . ∴ and ∴ LHS = = = = = = RHS Hence Proved ! Please do press “Heart” button if you liked the solution.
Prove that (cosec 2 θ – sec 2 θ) / (cosec 2 θ + sec 2 θ) = 3/4, if tan θ = 1/√7. Read More »
Q) A person standing on the bank of a river observes that the angle of elevation of the top of a tower on the opposite bank is 60°. When he moves 30 m away from the bank, he finds the angle of elevation to be 30°. Find the height of the tower and width of
A person standing on the bank of a river observes that the angle of elevation of the top Read More »
Q) The angle of elevation of an aircraft from a point A on the ground is 60°. After a flight of 30 seconds, the angle of elevation changes to 30°. The aircraft is flying at a constant height of 3500√3 m at a uniform speed. Find the speed of the aircraft. Ans: Let’s start with the
Q) If the sum of first m terms of an A.P. is same as sum of its first n terms (m ≠ n), then show that the sum of its first (m + n) terms is zero. Ans: Step 1: We know that the sum of first m terms of an AP is given by: Sm
Q) In an A.P., the sum of three consecutive terms is 24 and the sum of their squares is 194. Find the numbers. Ans: Step 1: Let’s consider that the middle term is A, first term is A – D and third term is A + D, here D is the common difference. By given 1st
Q) If √2 is given as an irrational number, then prove that (5 – 2√2) is an irrational number. Ans: STEP BY STEP SOLUTION Let’s start by considering 5 – 2 √2 is a rational number. ∴ 5 – 2 √2 = (here p and q are integers and q ≠ 0) ∴ –