Question

how to factorize
2sin^2x-3sin x-2

Answer 1

assume sin x =t
then it becomes
2t^2 - 3t-2=0
now you are familiar???

Answer 2

hmm ... wel u see i hav a problem in factorizing polynomials .can u hlp?

Answer 3

hw do u actually factorize polynomials like these??i mean whats the method or steps to be followed?

Answer 4

2t^2 - 4t +t-2=0
2t(t-2)+1(t-2)=0
(2t+1)(t-2)=0

Answer 5

i feel some polynomials are non-intutive to be factorized by looking

Answer 6

it's called factoring by grouping

Answer 7

means wel how do u get intution that which term is to be grouped?

Answer 8

try to break the middle term in to two numbers such that sum is equal to the value of b and product is c in the quadratic eq. ax^2 + bx + c=0

Answer 9

...of course, there is no substitute for practice when it comes to developing an intuition on such things

Answer 10

wel what to do if it involves cubic expressions?

Answer 11

@aravindG do you get it???
yes @turingtest these can be developed effectively through practice.

Answer 12

that depends

Answer 13

like x^3-4x^2+4x

Answer 14

take x common

Answer 15

you can factor an x out, then factor the remaining quadratic

Answer 16

then the same way!!!

Answer 17

oh wow can u xplain this method of factorizing a quadratic

Answer 18

i mean sum in middle product in end

Answer 19

if you add -4 and +1 you get -3 (only such combination possible) while their product is also -4 matching the question..so you can proceed..

Answer 20

oh thx i had a prob in that part i hav one more qn pls help i will post separately