first substitute sina in place of x.....get an equation....
the substitute cos a ...get an equation......add both of them.....
psin2a+qsina+x=0
pcos2a+qcosa+r=0
OpenStudy (anonymous):
\[\sin \theta X \cos \theta = r/p\]
OpenStudy (anonymous):
adding both of them...
P+q(sina +cosa)+2r=0
but sina+cos a =-q/p(sum of roots)
p+q(-q/p)+2r=0
p^2-q^2+2rp=o
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OpenStudy (anonymous):
@THE_PROPHET i cant understand
OpenStudy (anonymous):
because sina and cosa ARE ROOTS OF THE EQUATION....they satisfy the equtaion....
so we can substitute sina and cosa in place of x to get the same value of 0....
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