Question

Can someone pls help me with these. I need to get the method of solving such questions.

Find the complete solution in radians of each equation.

a) 2sin^2A + cosA - 1 = 0
b) sin^2A - 1 = cos^2A
c) 2sinA + 1 = cscA

Answer 1

play around with identities to change how the problems look

Answer 2

In a) should I substitute 1- cos^2A for sin^2A ??

Answer 3

id give it a shot and see what happens, yes

Answer 4

The book does not have such sums solved as example but they are given in the exercise....

Answer 5

these look like they can turn into quadratic equations

Answer 6

Yes somebody did suggest such a course of action but I have no examples to see , understand and follow..

Answer 7

2sin^2 + cos - 1 = 0

2(1-cos^2) + cos - 1 = 0

2- 2cos^2 + cos - 1 = 0

- 2cos^2 + cos + 1 = 0

2cos^2 - cos - 1 = 0

cosA = (-b +- sqrt(b^2-4ac))/2a

Answer 8

can i find some solved examples on some website???

Answer 9

im sure you can, i just dunno where.

if you wanna try some practice problems, try interactmath.com

its free and has solutions that you can thumb thru as well

Answer 10

hit enter, pick a book that matches your material, and play away :)

Answer 11

Thanks, I'll try the site..

Answer 12

good luck :)