Question

If ANYONE could help ASAP Pls

Answer 1

ANSWER

The correct answer is C

EXPLANATION

This is the composition the two functions

We have

$a(x) = 3x + 1$

and

$b(x) = \sqrt{x - 4}$

$(b \circ \: a)(x) = b(a(x))$

$(b \circ \: a)(x) = b(3x + 1)$

We substitute to obtain,

$(b \circ \: a)(x) = \sqrt{(3x + 1) - 4}$

$(b \circ \: a)(x) = \sqrt{3x - 3}$

The domain of this function can be found by solving,

$3x - 3 \geqslant 0$

This implies that

$3x \geqslant 3$

Or

$x \geqslant 1$

In interval notation, we have,

$[1, \infty )$

The correct answer is option C