Question 9 - NCERT Exemplar - MCQ - Chapter 8 Class 10 Introduction to Trignometry

Last updated at July 21, 2026 by

The value of (tan 1° tan 2° tan 3° ... tan 89°) is

(A) 0   (B) 1   (C) 2   (D)

The value of (tan 1° tan 2° tan 3° ... tan 89°) is - MCQ - Trigonometr - NCERT Exemplar - MCQ

part 2 - Question 9 - NCERT Exemplar - MCQ - Serial order wise - Chapter 8 Class 10 Introduction to Trignometry

Take a fresh quiz. Then take another.
Every attempt is a new AI-adaptive Teachoo quiz with 5 questions, selected from your answers, mistakes, and progress.
Remove Ads

Transcript

Question 9 The value of (tan 1° tan 2° tan 3° ... tan 89°) is (A) 0 (B) 1 (C) 2 (D) tan 1° tan 2° tan 3° ... tan 89° = tan 1° tan 2° tan 3° … tan 44° tan 45° tan 46° … tan 87° tan 88° tan 89° Using tan θ = cot (90° − θ) = tan 1° tan 2° tan 3° … tan 44° tan 45° cot (90° − 46°) … cot (90° − 87°) cot (90° − 88°) cot (90° − 89°) = tan 1° tan 2° tan 3° … tan 44° tan 45° cot 44° … cot 3° cot 2° cot 1° = tan 1° cot 1° tan 2° cot 2° tan 3° cot 3° … tan 44° cot 44° × tan 45° = tan 1° × 𝟏/(𝒕𝒂𝒏 𝟏°) . tan 2° × 𝟏/(𝒕𝒂𝒏 𝟐°) . tan 3° × 𝟏/(𝒕𝒂𝒏 𝟑°) … tan 44° × 𝟏/(𝒕𝒂𝒏 𝟒𝟒°) × tan 45° = 1 . 1 . 1 … 1 × tan 45° = tan 45° = 1 So, the correct answer is (B)

Davneet Singh's photo - Co-founder, Teachoo

Made by

Davneet Singh

Davneet Singh is an IIT Kanpur graduate and has been teaching for 16+ years. At Teachoo, he breaks down Maths, Science and Computer Science into simple steps so students understand concepts deeply and score with confidence.

Many students prefer Teachoo Black for a smooth, ad-free learning experience.