The set of values of $m$ for which $m x ^ { 2 } - 6 m x + 5 m + 1 > 0$ for all real $x$ is (a) $m < \frac { 1 } { 4 }$ (b) $m \geq 0$ (c) $0 \leq m \leq \frac { 1 } { 4 }$ (d) $0 \leq m < \frac { 1 } { 4 }$.
(d) Calculate the discriminant $\left( b ^ { 2 } - 4 a c \right)$ of the given quadratic.
The set of values of $m$ for which $m x ^ { 2 } - 6 m x + 5 m + 1 > 0$ for all real $x$ is\\
(a) $m < \frac { 1 } { 4 }$\\
(b) $m \geq 0$\\
(c) $0 \leq m \leq \frac { 1 } { 4 }$\\
(d) $0 \leq m < \frac { 1 } { 4 }$.