定積分 $\int_{-a}^{a} (\sin{2x} + \cos{3x} + x^4 + \frac{3}{2}x + 2) dx$ を計算する問題です。解析学定積分積分計算三角関数多項式関数2025/7/131. 問題の内容定積分 ∫−aa(sin2x+cos3x+x4+32x+2)dx\int_{-a}^{a} (\sin{2x} + \cos{3x} + x^4 + \frac{3}{2}x + 2) dx∫−aa(sin2x+cos3x+x4+23x+2)dx を計算する問題です。2. 解き方の手順まず、積分を各項に分解します。∫−aasin2xdx+∫−aacos3xdx+∫−aax4dx+∫−aa32xdx+∫−aa2dx\int_{-a}^{a} \sin{2x} dx + \int_{-a}^{a} \cos{3x} dx + \int_{-a}^{a} x^4 dx + \int_{-a}^{a} \frac{3}{2}x dx + \int_{-a}^{a} 2 dx∫−aasin2xdx+∫−aacos3xdx+∫−aax4dx+∫−aa23xdx+∫−aa2dx次に、各項の積分を計算します。∫−aasin2xdx=[−12cos2x]−aa=−12cos2a−(−12cos−2a)=−12cos2a+12cos2a=0\int_{-a}^{a} \sin{2x} dx = \left[-\frac{1}{2}\cos{2x}\right]_{-a}^{a} = -\frac{1}{2}\cos{2a} - (-\frac{1}{2}\cos{-2a}) = -\frac{1}{2}\cos{2a} + \frac{1}{2}\cos{2a} = 0∫−aasin2xdx=[−21cos2x]−aa=−21cos2a−(−21cos−2a)=−21cos2a+21cos2a=0∫−aacos3xdx=[13sin3x]−aa=13sin3a−13sin−3a=13sin3a+13sin3a=23sin3a\int_{-a}^{a} \cos{3x} dx = \left[\frac{1}{3}\sin{3x}\right]_{-a}^{a} = \frac{1}{3}\sin{3a} - \frac{1}{3}\sin{-3a} = \frac{1}{3}\sin{3a} + \frac{1}{3}\sin{3a} = \frac{2}{3}\sin{3a}∫−aacos3xdx=[31sin3x]−aa=31sin3a−31sin−3a=31sin3a+31sin3a=32sin3a∫−aax4dx=[15x5]−aa=15a5−15(−a)5=15a5+15a5=25a5\int_{-a}^{a} x^4 dx = \left[\frac{1}{5}x^5\right]_{-a}^{a} = \frac{1}{5}a^5 - \frac{1}{5}(-a)^5 = \frac{1}{5}a^5 + \frac{1}{5}a^5 = \frac{2}{5}a^5∫−aax4dx=[51x5]−aa=51a5−51(−a)5=51a5+51a5=52a5∫−aa32xdx=[34x2]−aa=34a2−34(−a)2=34a2−34a2=0\int_{-a}^{a} \frac{3}{2}x dx = \left[\frac{3}{4}x^2\right]_{-a}^{a} = \frac{3}{4}a^2 - \frac{3}{4}(-a)^2 = \frac{3}{4}a^2 - \frac{3}{4}a^2 = 0∫−aa23xdx=[43x2]−aa=43a2−43(−a)2=43a2−43a2=0∫−aa2dx=[2x]−aa=2a−2(−a)=2a+2a=4a\int_{-a}^{a} 2 dx = \left[2x\right]_{-a}^{a} = 2a - 2(-a) = 2a + 2a = 4a∫−aa2dx=[2x]−aa=2a−2(−a)=2a+2a=4aしたがって、積分は次のようになります。0+23sin3a+25a5+0+4a0 + \frac{2}{3}\sin{3a} + \frac{2}{5}a^5 + 0 + 4a0+32sin3a+52a5+0+4a3. 最終的な答え23sin(3a)+25a5+4a\frac{2}{3}\sin(3a) + \frac{2}{5}a^5 + 4a32sin(3a)+52a5+4a