Forum

Raavi Tiwari
@raavi-tiwari
Noble Member
Joined: May 7, 2021
Last seen: Jun 14, 2021
Topics: 0 / Replies: 2064
Reply
Answer to: Express sin 67° + cos 75° in terms of trigonometric ratios of angles between 0° and 45°.

Given, sin 67° + cos 75° sin 67° = sin (90° – 23°) cos 75° = cos (90° – 15°) So, sin 67° + cos 75° = sin (90° – 23°) + cos (90° – 15°) Now, ...

4 years ago
Reply
Answer to: If A, B and C are interior angles of a triangle ABC, then show that sin (B + C/2) = cos A/2

We know that, for a given triangle, sum of all the interior angles of a triangle is equal to 180° A + B + C = 180° ….(1) To find the value of (B+ ...

4 years ago
Reply
Answer to: If sec 4A = cosec (A – 20°), where 4A is an acute angle, find the value of A.

sec 4A = cosec (A – 20°) We know that sec 4A = cosec (90° – 4A) To find the value of A, substitute the above equation in the given problem cosec...

4 years ago
Reply
Answer to: Find the remainder, when the polynomial 2x 4 +x 3 + 4x 2 - 3x−2 is divided by x−3 (without applying long division).

remainder=214 explanation: x - 3 x = 3 p(x) =2(3)4 + 3(3) + 4(3)2 - 3(3)-2 p(x) = 162 + 27 + 36 - 9 - 2 p(x) = 214

4 years ago
Forum
Reply
Answer to: If tan A = cot B, prove that A + B = 90°.

tan A = cot B We know that cot B = tan (90° – B) To prove A + B = 90°, substitute the above equation in the given problem tan A = tan (90° – B) ...

4 years ago
Reply
Answer to: If tan 2A = cot (A – 18°), where 2A is an acute angle, find the value of A.

tan 2A = cot (A- 18°) We know that tan 2A = cot (90° – 2A) Substitute the above equation in the given problem ⇒ cot (90° – 2A) = cot (A -18°) ...

4 years ago
Reply
Answer to: Show that: (i) tan 48° tan 23° tan 42° tan 67° = 1 (ii) cos 38° cos 52° – sin 38° sin 52° = 0

(i) tan 48° tan 23° tan 42° tan 67° We know that, tan 48° = tan (90° – 42°) = cot 42° tan 23° = tan (90° – 67°) = cot 67° = tan (90° – 42°) tan ...

4 years ago
Reply
Answer to: Evaluate : (i) cos 48° – sin 42° (ii) cosec 31° – sec 59°

(iii) cos 48° – sin 42° We know that, 48° is written as 90° – 42°, which is equal to the sin 42°. = cos (90° – 42°) – sin 42° Substitute the val...

4 years ago
Reply
Answer to: Evaluate : (i) sin 18°/cos 72° (ii) tan 26°/cot 64°

(i) We know that, 18° is written as 90° – 18°, which is equal to the cos 72°. = sin (90° – 18°) /cos 72° Substitute the value, to simplify this...

4 years ago
Reply
Answer to: sin (A + B) = sin A + sin B. (ii) The value of sin θ increases as θ increases. (iii) The value of cos θ increases as θ increases

(i) False. Let us take A = 30° and B = 60°, then Substitute the values in the sin (A + B), we get sin (A + B) = sin (30° + 60°) = sin 90° = 1 an...

4 years ago
Reply
Answer to: If tan (A + B) = √3 and tan (A – B) = 1/√3, 0° < A + B ≤ 90°; A > B, find A and B.

tan (A + B) = √3 Since √3 = tan 60° Now substitute the degree value tan (A + B) = tan 60° (A + B) = 60° …....(i) The above equation is assum...

4 years ago
Reply
Answer to: 2tan30°/1-tan^2 30° = (A) cos 60° (B) sin 60° (C) tan 60° (D) sin 30°

Correct option: (C) tan 60° Explanation: Substitute the of tan 30° in the given equation tan 30° = 1/√3 2tan30°/1-tan230° = 2(1/√3)/1-(1/√3)2...

4 years ago
Reply
Answer to: sin 2A = 2 sin A is true when A = (A) 0° (B) 30° (C) 45° (D) 60°

Correct option:(A) 0° Explanation: To find the value of A, substitute the degree given in the options one by one sin 2A = 2 sin A is true when A...

4 years ago
Reply
Answer to: 1 - tan^245°/1+tan^245° = (A) tan 90° (B) 1 (C) sin 45° (D) 0

Correct option: (D) 0 Explanation: Substitute the of tan 45° in the given equation tan 45° = 1 1-tan245°/1+tan245° = (1-12)/(1+12) = 0/2 = 0

4 years ago
Reply
Answer to: Choose the correct option and justify your choice : 2tan 30°/1+tan230° = (A) sin 60° (B) cos 60°

Correct option: (A) sin 60° Explanation: Substitute the of tan 30° in the given equation tan 30° = 1/√3 2tan 30°/1+tan230° = 2(1/√3)/1+(1/√3)2...

4 years ago
Reply
Answer to: Why do you think the nationalist movement supported the idea that all adults have a right to vote?

The national movement supported the idea that all adults have a right to vote because of the following reasons: Every responsible citizen should p...

4 years ago
Reply
Answer to: Write a brief note on the Members of Parliament.

The Members of Parliament are from different backgrounds. Many members are from rural areas and from regional parties. Groups and peoples that were ...

4 years ago
Reply
Answer to: What is ‘Question hour’ in Parliament?

The first hour of every sitting during a Parliament Session is called the Question Hour. During ‘Question hour’ Questions are posed by members to spec...

4 years ago
Reply
Answer to: How is a National government selected?

After the Lok Sabha elections, a list is prepared showing how many MPs belonging to each political party have won the elections. The Political party w...

4 years ago
Page 3 / 104

How Can We Help?