Evaluate $\frac { - b + \sqrt { b ^ { 2 } - 4 a c } } { 2 a }$ for a = 4, b = 2, $c = - \frac { 3 } { 4 }$
A) 4
B) $\frac { 3 } { 7 }$
C) $\frac { 1 } { 4 }$
D) none of these

Question

Quizplus · Accepted Answer

Substituting the given values of a, b, and c in the given expression, we get:

$\frac{-2+\sqrt{2^2-4\cdot4\cdot\left(-\frac{3}{4}\right)}}{2\cdot4}$

Simplifying the expression inside the square root:

$\frac{-2+\sqrt{4+12}}{8} = \frac{-2+\sqrt{16}}{8}$

$\frac{-2+4}{8} = \frac{1}{4}$

Therefore, the value of the given expression is $\frac{1}{4}$, which corresponds to choice C.

Evaluate −b+b2−4ac2a\frac { - b + \sqrt { b ^ { 2 } - 4 a c } } { 2 a }2a−b+b2−4ac​​

Evaluate $\frac { - b + \sqrt { b ^ { 2 } - 4 a c } } { 2 a }$