1.

Find the square root of 12+2 under root 35​

Answer»

Step-by-step:

Since \sf{\sqrt{35} =\sqrt{5} \times\sqrt{7} }, there must be two square roots.

Let the value \sf{12+2\sqrt{35} } be a square of some number \sf{\sqrt{a} +\sqrt{b} }.

\sf{\implies (\sqrt{a} +\sqrt{b} )^2=12+2\sqrt{35} }

\sf{\implies a+2\sqrt{ab} +b=12+2\sqrt{35} }

\sf{\implies a+b=12\;and\;ab=35}

\sf{\therefore Two\;numbers\;are\;5\;and\;7.}

So the value was a square of \sf{\sqrt{7} +\sqrt{5} }.

Hence the square ROOT of the GIVEN value is \sf{\sqrt{7} +\sqrt{5} }.

Learn more:

We approach with the ALGEBRAIC identity \sf{(x+y)^2=x^2+2xy+y^2}.

And when a number is SQUARED, its square root should be the original number.

Extra question: Find the square root of \sf{12+4\sqrt{3} +4\sqrt{5} +2\sqrt{15} }.

You could solve this with \sf{(x+y+z)^2=x^2+y^2+z^2+2xy+2yz+2zx}.

Hope this helps.



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