CAN ANYBODY SOLVE THIS QUESTION ?? NEED HELP!!! The number of irrational solutions of the equation \[\sqrt{x ^{2}+\sqrt{x ^{2}+11}}+\sqrt{x ^{2}-\sqrt{ x ^{2} +11}} = 4\] is a.) 0 b.)2 c.)4 d.)infinite justify your answer with a proof. (topic - quadratic equations)
@dan815
@IrishBoy123
use substitution
\[\sqrt{x ^{2}+\sqrt{x ^{2}+11}}+\sqrt{x ^{2}-\sqrt{ x ^{2} +11}} = 4\] Alright! substituting \(\sqrt{x^2+11}=u~~\implies~~ x^2=u^2-11\) the equation then becomes \[\sqrt{u^2+u-11}+\sqrt{u^2-u-11} = 4\]
you still cant square both sides
complete the square?
im actually thinking of rationalising the left hand side expression
but idk how useful it is..
completing the square doesn't look that primising..
you can try
YOU'RE RATIONAL leave to me im irrational
...
you're more like complex/imaginary danny
i gave up rationalising half way as it got really complicated
what do i do now, haha. i dont even go to school.
we are supposed to solve these questions in less than 2 min -_-
so there ought to be some trick
ok i just expanded it
is that easier to solve?
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