In a triangle ABC, 2ac sin 1/2 (A – B + C) =
(A) a2+b2-c2 (B) c2+a2-b2
(C) b2-c2-a2 (D) c2-a2-b2

Question

In a triangle ABC, 2ac sin 1/2 (A &ndash; B + C) = (A) a 2 +b 2 -c 2 (B) c 2 +a 2 -b 2 (C) b 2 -c 2 -a 2 (D) c 2 -a 2 -b 2

Ramesh V · Answer

A+B+C=Pi

so A+C = Pi - B

so here it will be : 2ac.sin(Pi/2 -B) = 2ac.cosB

by cosine rule, we have: c²+a²-b² = 2ac cos B

option B

--

Please feel free to post as many doubts on our disucssion forum as you can. If you find any question difficult
to understand - post it here and we will get you the answer and detailed solution very quickly.We are all
IITians and here to help you in your IIT JEE preparation. All the best.

Regards,
Ramesh
IIT Kgp - 05 batch

Thank you for registering.

Register Now and Win Upto 25% Scholorship for a Full Academic Year !

Enter Your Details

Registration done!

In a triangle ABC, 2ac sin 1/2 (A – B + C) = (A) a 2 +b 2 -c 2 (B) c 2 +a 2 -b 2 (C) b 2 -c 2 -a 2 (D) c 2 -a 2 -b 2

In a triangle ABC, 2ac sin 1/2 (A – B + C) =
(A) a2+b2-c2 (B) c2+a2-b2
(C) b2-c2-a2 (D) c2-a2-b2

1 Answers

Think You Can Provide A Better Answer ?

Provide a better Answer & Earn Cool Goodies See our forum point policy

Other Related Questions on Trigonometry

ASK QUESTION

Answer and earn gift vouchers

View courses by askIITians

Design classes One-on-One in your own way with Top IITians/Medical Professionals

Complete Self Study Package designed by Industry Leading Experts

Live 1-1 coding classes to unleash the Creator in your Child

a Complete All-in-One Study package Fully Loaded inside a Tablet!

Register Now & Win Upto 25% Scholorship

Thank you for registering.

Register Now and Win Upto 25% Scholorship for a Full Academic Year !

Enter Your Details

Registration done!

In a triangle ABC, 2ac sin 1/2 (A – B + C) = (A) a 2 +b 2 -c 2 (B) c 2 +a 2 -b 2 (C) b 2 -c 2 -a 2 (D) c 2 -a 2 -b 2

In a triangle ABC, 2ac sin 1/2 (A – B + C) = (A) a2+b2-c2 (B) c2+a2-b2 (C) b2-c2-a2 (D) c2-a2-b2

1 Answers

Think You Can Provide A Better Answer ?

Provide a better Answer & Earn Cool Goodies See our forum point policy

Other Related Questions on Trigonometry

ASK QUESTION

Answer and earn gift vouchers

View courses by askIITians

Design classes One-on-One in your own way with Top IITians/Medical Professionals

Complete Self Study Package designed by Industry Leading Experts

Live 1-1 coding classes to unleash the Creator in your Child

a Complete All-in-One Study package Fully Loaded inside a Tablet!

Register Now & Win Upto 25% Scholorship

In a triangle ABC, 2ac sin 1/2 (A – B + C) =
(A) a2+b2-c2 (B) c2+a2-b2
(C) b2-c2-a2 (D) c2-a2-b2