Question

explain how the third step is come from the second step​

Answer 1

Answer:

1 = $\sqrt{ (0.25 + 0.64) + c^{2} }$

squaring both sides,

$1^{2}$ = (0.25 + 0.64) + $c^{2}$

$c^{2}$ = 1 - (0.25 + 0.64)

$c^{2}$ = 1 - 0.89

c = +-$\sqrt{1- 0.89}$