The square root of 0.09 + 2 × 0.21 + 0.49 is (a) √0.09 + √0.49 (b) 2√0.21 (c) 1 (d) 0.58

Question

The square root of 0.09 + 2 × 0.21 + 0.49 is 

(a) \(\sqrt{0.09} + \sqrt{0.49}\) 

(b) \(\sqrt[2] {0.21}\) 

(c) 1 

(d) 0.58

Answer 1

(c) 1

\(\sqrt{0.09+2\times0.3\times0.7+(0.7)^2}\)

= \(\sqrt{(0.3)^2+2\times0.3\times0.7+(0.7)^2}\)

= \(\sqrt{(0.3+0.7)^2}\)

=\(\sqrt 1\) = 1