What is componendo and dividendo method? Plz explain.

1. cos 20 cos40 cos 60 cos 80=1/16
   

cos20.cos40.cos80=1/8

 Prove that.....Tan 70 = tan 20 + 2 tan 50...

Solve Sinx + Sin3x + Sin5x = 0.

cot(2pi+x)=?

sin 20 sin 40 sin 60 sin 80=3/16

can we find the value(in degrees) of tan(4/3)

solution of ml agarwal for isc 11std

Q: prove that cos³ x+ cos³ ( 2pi/3 ) + x ) + cos³(2pi/3 )- x)=3/4cos 3x.

The chapter trigonometry in RS Aggarwal book (of class 11th) is divided into 6 sub-chapters. But its chapter 5 ( Solution of triangles ) and 6 ( Graphs of trigonometric functions ) are not the topics of NCERT Book.

Now my question is: Should I study these two chapters (5 &6 of RS Aggarwal) as these are not in NCERT Book?

prove the following :

root 3 cosec 20 - sec 20 = 4

prove that tan20 .tan40.tan80=tan60.

sin⁴x+cos⁴x=1-2sin²xcos²x

cos²x + cos²(x + pi/3) + cos²(x - pi/3) = 3/2. prove

cotx cot2x - cot2x cot3x-cot3x cotx=1

Prove that sin(a) + sin(a+h) + sin(a+2h) +.........+ sin(a+(n-1)h) = (sin(nh/2) sin(a+(n-1)h/2)/sin(h/2)

sinA . sin(60-A) . sin(60+A) = 1/4 sin3A

if sin alpha + sin beta= a and cos alpha + cos beta= b, show that

1. Sin(alpha+beta)= 2ab/a sq.+b sq.

2. Cos(alpha+beta)= b sq.-a sq./b sq.+a sq.

prove that cos20 cos 40 cos 60 cos 80=1/16.

 minimum value of sec square theta + cosec square theta 

prove that cos 10.cos30.cos50.cos70 = 3/16

prove that

( cos 17 +sin 17 )/(cos 17-sin17) = tan 62

prove that tan 50 = 2 tan 10 + tan40

Find the value of tan 480 degrees?

1.(1+cos pi/ 8) (1+cos 3pi / 8) (1+cos 5pi / 8) (cos 7pi / 8)=1/8

Prove that sin3x + sin 2x – sinx = 4 sinx cos x/2 cos3x/2

sin10*sin50*sin70=1/8?

prove that

tan (A+30) + cot (A-30)=1/(sin2A-sin60)

sin 105 degree +cos 105 degree =cos 45 degree

Prove the following: cosA / 1 - sinA = tan (45 + A/2)

Find the maximum and minimum values of sin^4x + cos^2x and hence or otherwise find the maximum value of sin^1000 x + cox^2008 x

cos4 pi /8+ cos4 3pi /8+ cos4 5pi /8 +cos4 7pi/ 8=3/2  prove it fast rely plssss

PROVE THAT

cos³A + cos³(120+A) + cos³(240+A) = 3/4 cos3A

cos4 pi / 8+cos4 3pi /8 + cos4 5pi / 8 +cos4 7pi /8 =3/2

prove that cos^2 x + cos^2 y - 2cosx cosy cos (x+y) = sin^2(x+y)

if A+B=45 degree.show that {1+tanA}{1+tanB}=2

1. An engine pumps 2000kgs of water in 1 minute to an average height of 10m.Calculate the power of the engine if 30% of the energy is wasted in the process.

2. A water pump of power 1.5KW draws water through a mean height of 10m to fill a tank 4m x 3m x 4m. Calculate the time taken to fill the tank

 Prove that:

4 cosA cos(60-A) cos(60+A) = cos3A

in any triangleABC P.T

(b²-c²)cotA + (c²-a²)cotB + (a²-b²)cotC = 0

Prove cos5x=16cos⁵x-20cos³x+5cosx

prove that cos11+sin11/cos11-sin11=tan56

Prove:Cos18+Sin18/Cos18-Sin18 = Tan63Please provide me the answer for this question as soon as possible...

prove using sine rule - 1) sin ( B-C)/2 = b-c/a cos ( A/2)

2)1+cos(A-B) cos C / 1+cos(A-C) cos B = a2+ b2/ a2- c2

3) (b-c)cot (A/2) + (c-a)cot (B/2) + (a-b)cot (C/2) = 0

4) a cos(B-C/2) = (b+c) sin(A/2)

5) c/(a-b) = tan(A/2) + tan(B/2) / tan(A/2) - tan(B/2)

6) a(cos C - cos B) = 2(b-c) cos^2 (A/2)

show that tan3x-tan2x-tanx =tan3x*tan2x*tanx

IF cos(alpha + beta) = 4/5 and sin(alpha - beta) = 5/13

FIND THE VALUE OF tan 2 alpha, where 0 is less than equal to alpha is less than equal to pie/4.

plz reply!!

How to find principal solutions of trigonometric equations?

 Prove that    tan4x= (4tanx(1-tan^2x)) / 1-6tan^x+tan^4x

a tree stands vertically on a hill side which makes an angle of 15degree with the horizontal. from a point on the ground 35m down the hill from the base of the tree, the angle of elevation of the top of the tree is 60degree. find the height of the tree.

ans(35root2m) plese tell the xact solution

Find the values of theta lying between between 0 degrees and 360 degrees when

1)sin theta=1/2

2)tan theta = -1

3)sec theta = -2

4)sin theta =sin 21 degrees

5)tan theta= -2.0145

6)sin theta=cos 317 degrees

7)cos theta=sin 285 degrees

Solve the equation:

4sinxcosx + 2sinx + 2cosx + 1 = 0

Show that cos 24 + cos 55 + cos 125 + cos 204 + cos 300= 1/2

prove-

cos²(pi /8) + cos^{2 (}3pi / 8) +cos²(5pi / 8) +cos^{2 (}7pi / 8) = 2

If A+B+C = pai, prove that

sinA + sinB + sinC = 4 cosA/2 cosB/2 cosC/2

find the derivative of cotx by the first principle?

The angles of a triangle are in AP and the ratio of the number of degrees in the least to the number of radians in the greatest is 60:π. Find the angles in degrees and radians.

prove sin²A - sin²B/sinA .cosA- sinB. cosB = tan(A+B)

Prove that : cosA cos2A cos4A cos8A =sin16A / 16sinA

prove that (secA secB + tanA tanB)² - (secA tanB +tanA secB)² = 1

Please explain working

prove that 1+cos2x+cos4x+cos6x= 4cosx cos2x cos3x.

EVALUATE cos(-1125)

Solve sin2x+sin4x+sin6x=0

prove that

cos20cos40cos60cos80 =1/16