Lesson#1 <br />Product to sum or difference forms and vice versa <br />Exercise 10.4 <br />Sum, Difference and Product of Sines and Cosines <br />Sum or diffrence form to Product form. <br />1) sinP+sinQ=2 sin((P+Q)/2)cos((P−Q)/2) <br />2) sinP−sinQ=2 cos((P+Q)/2)sin((P−Q)/2) <br />3) cosP+cosQ=2 cos((P+Q)/2)cos((P−Q)/2) <br />4) cosP−cosQ=−2 sin((P+Q)/2)sin((P−Q)/2) <br />Prove that: <br />1) 2 sinα cosβ=sin(α+β)+sin(α−β) <br />2) 2 cosα sinβ=sin(α+β)−sin(α−β) <br />3) 2 cosα cosβ=cos(α+β)+cos(α−β) <br />4) −2 sinα sinβ=cos(α+β)−cos(α−β) <br />Math.Ex.10.4, Part12-10.4 <br />1) sinP+sinQ=2 sin((P+Q)/2)cos((P−Q)/2) <br />1) sinP−sinQ=2 cos((P+Q)/2)sin((P−Q)/2) <br />1) cosP+cosQ=2 cos((P+Q)/2)cos((P−Q)/2) <br />1) cosP−cosQ=−2 sin((P+Q)/2)sin((P−Q)/2) <br />Trigonometric Identities <br />Chapter No 10 <br />Exercise No 10.4 <br />Mathematics <br />part 1
