BREAKING: Target Test Prep releases Brand New 2026 On Demand GMAT prep course

Redeem
TTP OnDemand GMAT Video Course
Featured Course

Target Test Prep GMAT OnDemand

Scott Woodbury-Stewart’s private virtual classroom — 400 hours of master-class video lessons for the GMAT Focus Edition.

  • 715+ score guarantee — highest in the industry (99th percentile)
  • 52 chapters · 1,500+ lessons · 4,000+ practice questions
  • 400 hours of video · 1,500+ instructor-led HD smartboard lessons
  • 300,000+ students accepted to Harvard, Stanford, Wharton, Booth & Sloan & more
  • 24/7 live support + weekly Zoom office hours with GMAT instructors
  • TTP AI Assist — 24/7 AI-powered virtual tutor for instant help
  • 1,200+ flashcards + AI-powered study assistant & daily calendar
  • OnDemand, LiveTeach & GMAT Bootcamp formats available
  • Also: GRE, SAT Math & Executive Assessment courses
  • MBA Admissions Consulting now available
  • 🏆 2025 EdTech Breakthrough Award: Test Prep Solution Provider of the Year
  • 200,000+ students served
  • 5-day free trial — $0 to start, no auto-billing, cancel anytime
★★★★★ 5.0 (559 reviews)
130-pt guarantee
$0 to start then $127/mo
Start Free 5-Day Trial Read 559 Reviews →

trigonometry

Expert replies
Post new topic Post Reply
Previous Topic Next Topic
User avatar
Senior | Next Rank: 100 Posts
Posts: 46
Joined: Fri Aug 19, 2011 12:13 amFollowed by: 1 member
Location: Delhi, India
by romitvsingh » Wed Jan 11, 2012 8:47 pm
the sin of angle B is 28/35. the angle measure is therefore sin -1( 28/35 ); angle B is approx 53.1 degree

My question is how do we get the value of angle B as 53.1 degree ?

pls explain in detail
Eat, sleep GMAT
Top
Join the discussion
Log in to postLogin with Googleuse password
QUOTE IN REPLY
Source: — Problem Solving |
User avatar
Legendary Member
Posts: 641
Joined: Wed Apr 20, 2011 1:15 amFollowed by: 32 members
Thanked: 149 times
GMAT Score:760

by avik.ch » Wed Jan 11, 2012 10:04 pm
You will never be asked to find the exact values of sin -1( 28/35 ).

What you can be asked is : Sin B = 28/35 then what is cos B or tan B. This seems logical.

Anyway, there is no way to find the exact value of 53.1 degree, unless you are provided with a trigonometric chart or a calculator.


Thanks !!
Top
Join the discussion
Log in to postLogin with Googleuse password
QUOTE IN REPLY
User avatar
Legendary Member
Posts: 588
Joined: Sun Oct 16, 2011 9:42 amFollowed by: 9 members
Location: New Delhi, India
Thanked: 130 times
GMAT Score:720

by rijul007 » Thu Jan 12, 2012 12:59 am
As avik.ch said
GMAT would never ask a question where you would need to find the value of sine inverse


But if you were given options such as these:
A. 17.4
B. 34.8
C. 43.9
D. 53.1
E. 69.3


Heres how I would have done it:
Sin(0) = 0
As we increase the angle, sin also increases until sin(90) = 1


sin(x) = 28/35 = 4/5 = 0.8
sin(45) = 1/sqrt(2) = 0.7
sin(45) < sin(x)
45<x
Option A, B, and C are eliminated

sin(60) = sqrt(3)/2 = 0.86
sin(60) > sin(x)
60 > x
Option E also eliminated

Option D is correct



If two options were given between 45 and 60, we cannot find the ans and neither does GMAT expect us to.
Top
Join the discussion
Log in to postLogin with Googleuse password
QUOTE IN REPLY
User avatar
GMAT Instructor
Posts: 15539
Joined: Tue May 25, 2010 12:04 pmFollowed by: 1906 members
Location: New York, NY
Thanked: 13060 times
GMAT Score:790

by GMATGuruNY » Thu Jan 12, 2012 1:19 am
Trigonometry is not tested on the GMAT. Any problem that discusses the sine, cosine or tangent of an angle -- or requires knowledge of these properties -- is not a legitimate GMAT question.
Private tutor exclusively for the GMAT and GRE, with over 20 years of experience.
Followed here and elsewhere by over 1900 test-takers.
I have worked with students based in the US, Australia, Taiwan, China, Tajikistan, Kuwait, Saudi Arabia -- a long list of countries.
My students have been admitted to HBS, CBS, Tuck, Yale, Stern, Fuqua -- a long list of top programs.

As a tutor, I don't simply teach you how I would approach problems.
I unlock the best way for YOU to solve problems.

For more information, please email me (Mitch Hunt) at [email protected].
Student Review #1
Student Review #2
Student Review #3
Top
Join the discussion
Log in to postLogin with Googleuse password
QUOTE IN REPLY
User avatar
Legendary Member
Posts: 641
Joined: Wed Apr 20, 2011 1:15 amFollowed by: 32 members
Thanked: 149 times
GMAT Score:760

by avik.ch » Thu Jan 12, 2012 1:40 am
The law has already been stated by Mitch sir.

That is the reason why OG never uses any trigonometry to explain any problems.
Top
Join the discussion
Log in to postLogin with Googleuse password
QUOTE IN REPLY
Post new topic Post Reply
• Page 1 of 1