you don't show the graph, but graphing y=x^2 it is a U shaped line that starts at (0,0) and the lines go upwards on both sides of the Y axis,
This means all real numbers above 0 and 0 will solve it
so the range is y≥0
Answer:
Nolan correctly identified the square numbers before and after 18.
The square roots of them are 4 and 5.
Clearly, square root of 18 should lie between 4 and 5 only.
He, then carefully squared 4.1, 4.2, 4.3 etc. and identified that 4.3 squared is nearer to 18.
Since, Nolan is finding estimated square root, his steps are cool and he didn't make any error.
<span>x^2 - 12x - 45
= (x - 15) (x + 3) .........</span><span>factored form</span>