Click to Chat

0120-4616500

CART 0

• 0

MY CART (5)

Use Coupon: CART20 and get 20% off on all online Study Material

ITEM
DETAILS
MRP
DISCOUNT
FINAL PRICE
Total Price: R

There are no items in this cart.
Continue Shopping
Get instant 20% OFF on Online Material.
coupon code: MOB20 | View Course list

Get extra R 150 off
USE CODE: SSPD25

```				   What is the value of :

cot 76 cot 44 + cot 44 cot 16 - cot 76 cot16
```

6 years ago

Share

```										Dear karthik,
E = cot(76)cot(44) + cot(44)cot(16) - cot(76)cot(16)   First, use the formula, cot(A) = tan(90 - A). Then we have :  E = tan(14)tan(46) + tan(46)tan(74) - tan(14)tan(74)  Rearrange this so the larger numbers are first : E = tan(46)tan(14) + tan(74)tan(46) - tan(74)tan(14)  Now we need these two formulae :  tan(A + B) = [tan(A) + tan(B)]/[1 - tan(A)tan(B)] which rearranges to : tan(A)tan(B) = 1 - [tan(A) + tan(B)]/tan(A + B) .......... (1) and tan(A - B) = [tan(A) - tan(B)] / [1 + tan(A)tan(B)] which rearranges to : tan(A)tan(B) = [tan(A) - tan(B)]/tan(A - B) - 1 ............ (2)  For the 1st expression of E, use (1) : tan(46)tan(14) = 1 - [tan(46) + tan(14)]/tan(60) But tan(60) = √3, so, tan(46)tan(14) = 1 - [tan(46 + tan(14)]/√3 = 1 - tan(46)/√3 - tan(14)/√3 ........... (3)  For the 2st expression of E, use (1) : tan(74)tan(46) = 1 - [tan(74) + tan(46)]/tan(120) But tan(120) = -√3, so, tan(74)tan(46) = 1 - [tan(74) + tan(46)]/(-√3) = 1 + tan(74)/√3 + tan(46)/√3 ..... (4)  For the 3st expression of E, use (2) : -tan(74)tan(14) = -{[tan(74) - tan(14)]/tan(60) - 1} But tan(60) = √3, so, -tan(74)tan(14) = -{[tan(74) - tan(14)]/√3 - 1} = -tan(74)/√3 + tan(14)/√3 + 1 .... (5)  Now add, (3) + (4) + (5), which gives the answer, E = 3.

All the best.
Win exciting gifts by answering the questions on Discussion Forum. So help discuss any                      query on askiitians forum and become an Elite Expert     League            askiitian.

Sagar Singh
B.Tech, IIT Delhi

```
6 years ago

# Other Related Questions on Trigonometry

proove that {cot^a(secA-1)}/1+sinA = sec^2A pls help me solve this problem and thak you

I hope you want to prove follwing identity. If yes then this not correct question as this can be never be true . For example put A = 45, LHS and RHS are not equal.

 Ajay 3 months ago

Hi Gaurang the question still does not seem to be correct. Can you post the screenshot of question attachment

 Ajay 3 months ago

Yes ajay sir I didnt type it correct so it was amistke please help in soving this one and thankyou very much

 Gaurang Kotasthane 3 months ago
In a right angled triangle the hypotenuse is four times as long as the perpendicular drawn to it from the opposite vertex. One of the acute angle is a)15° b)30° c)45° d) none of these

So let the triangle of sides ab, bc and ac, where ac is the hypotenuse of side 4x and the opposite perpendicular side ab is x . Let the angle you needs to find is y. Sin(y) = opposite /...

 Sakshi one month ago

Sorry but I didn`t get the language plz explain it in english And explain it step by step............... ...............

 Vaibhavi one month ago

c is the answer euto erouh kjghuf oeifdhiv oasidjfh pofhr vjdfbf uerhg iknf lfiisrn liedvnnv lrinjf fdsjkfj vdfkjns sdljnf lsdfof ilfeki

 uortoiei one month ago
Q3,4............................................................

By Cauchy Schwarz Ineq you have Let a+b+c+d+e = t. Then we need to prove that t 2 /(t-5) 20 which is equivalent to ptoving that t 2 -20t+100 = (t-10) 2 \ge 0 which is true as any perfect...

 mycroft holmes 27 days ago

Further we have and hence we must have Finally , from which we immediately have …........................................................................................

 mycroft holmes 27 days ago
If 2a+b+2c=0, then the family of lines ax+by+c=0 is concurrent at

Make ax+by+c=0 similar to 2a + b + 2c = 0 therfore multiply ax+by+c=0 by 2 .i.e. 2ax + 2by + 2c = 0 Now compare it with the coeff. of 2a+b+2c=0 we get, x = 1 y = ½ thus at this point it is...

 Vikas TU 3 months ago
Can we divide two vectors .....,....................... .....,....................... .... ... ... .... .... .... ............. ....

No! We cannot divide two vectors, when the mathematics of vectors was developed there has been no formal defination of division of vectors

 Riddhish Bhalodia 9 months ago

No! Actually not We cannot divide two vectors, when the mathematics of vectors was developed there has been no formal defination of division of vectors

 Ankit Jaiswal 8 months ago
View all Questions »

• Complete JEE Main/Advanced Course and Test Series
• OFFERED PRICE: R 15,000
• View Details
Get extra R 3,750 off
USE CODE: SSPD25

Get extra R 150 off
USE CODE: SSPD25

More Questions On Trigonometry