Can any kind soul help me in the below?
Please assist in (b)
a) Factorise t^4 - 16
b) If (x + 2/x)^2 = 36, then what is (x^2 + 2/x^2)^2?
Well, a) is easy, if you note that (or ).
Second question : I guess there is another more clever way to do this but I would have solved for first, then evaluated.
Since , we have , thus , therefore , so , and so, .
By means of the quadratic formula (for example), you find that equals that value and that value, then you substitute your results back into the second equation and evaluate.
Does that make sense ?