Use the trigonometric function values of the quadrantal angles to evaluate. \( 6 \cos 90^{\circ}+4 \cos 0^{\circ}+4\left(\cos 0^{\circ}\right)^{2} \) \( 6 \cos 90^{\circ}+4 \cos 0^{\circ}+4\left(\cos 0^{\circ}\right)^{2}=\square \) (Simplify your answer. Type an integer or a fraction.) ? 1.6 .89 ,

To evaluate the expression: \[ 6 \cos 90^{\circ} + 4 \cos 0^{\circ} + 4\left(\cos 0^{\circ}\right)^{2} \] We use the known values of the cosine function at the quadrantal angles: \[ \cos 0^{\circ} = 1 \quad \text{and} \quad \cos 90^{\circ} = 0 \] Substituting these values into the expression: \[ 6 \cos 90^{\circ} + 4 \cos 0^{\circ} + 4\left(\cos 0^{\circ}\right)^{2} = 6(0) + 4(1) + 4(1)^2 \] Simplifying each term: \[ 0 + 4 + 4 = 8 \] **Answer:** 8