Which inequality represents all values of x for which the pr

Which inequality represents all values of x for which the product below is defined? squareroot x - 6. squareroot x + 3 x greaterthanorequalto 6 x greaterthanorequalto -3 x lessthanorequalto 6 x greaterthanorequalto 0

Solution

f(x) = sqrt (x - 6)*sqrt (x + 3)

f(x) = f1(x)*f2(x)

f1(x) = sqrt (x - 6)

x - 6 >= 0

x >= 6

f2(x) = sqrt (x + 3)

x + 3 >= 0

x >= -3

So x >= 6 OR x >= -3

means

x >= 6

Option A is correct answer.