Evaluate <span class="katex-r" data-latex="displaystyle ∫_C 6xe^y dx + (3x^2 + y + 1)e^y dy"></span>, whe <span class="katex-r" data-latex="displaystyle C : x = cos^3 t, y = s∈^3 t"></span> with <span class="katex-r" data-latex="displaystyle 0 le t le ac{π}{2}"></span>.