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BodhiAI
Nov. 9, 2019

Trignometric Ratios For Sum & Difference of Angles,Conversion of Product into sum or difference:

A. Trigonometrical Ratios of Sum & Difference

a) sin (A+B) = sin A cosB + cosA sinB

b) sin (A-B) = sinA cosB - cosA sinB

c) cos (A+B) = cosA cosB - sinA sinB

d) cos(A-B) = cosA cosB + sinA sinB

e) tan (A+B)

f)

where A, B and

g)

h) where A, B and

i)

j)







B. Trigonometrical Ratios Involving Double Angles & Half Angles

a)

b)

or

c)

or

or

or

d) where

e)

f) where

g) where

h) where

C. Sum or Difference into Proucts

a)

b)

c)

d)

e) where, A, B

f) where, A, B

g)

h) where, A, B



D. Product Into Sum or Difference 

a)

b)

c)

d)

Note that in the last of these formulae the term cost (A-B) is in the first place.