∫(1-x)/√(9-4x²) dx設x=√(9/4)*sinθ,dx=(3/2)cosθ dθsinθ=2x/3,cosθ=√(9-4x²)/3原式= ∫(1-3/2*sinθ)/(3cosθ) * (3/2)cosθ dθ= (1/2)∫ dθ - (3/4)∫sinθ dθ= (1/2)arcsin(2x/3) +(3/4)cosθ + C= (1/2)arcsin(2x/3) + (1/4)√(9-4x²) + C
擴充套件資料
∫(1-x)/√(9-4x²) dx設x=√(9/4)*sinθ,dx=(3/2)cosθ dθsinθ=2x/3,cosθ=√(9-4x²)/3原式= ∫(1-3/2*sinθ)/(3cosθ) * (3/2)cosθ dθ= (1/2)∫ dθ - (3/4)∫sinθ dθ= (1/2)arcsin(2x/3) +(3/4)cosθ + C= (1/2)arcsin(2x/3) + (1/4)√(9-4x²) + C
擴充套件資料
不定積分的公式1、∫ a dx = ax + C,a和C都是常數2、∫ x^a dx = [x^(a + 1)]/(a + 1) + C,其中a為常數且 a ≠ -13、∫ 1/x dx = ln|x| + C4、∫ a^x dx = (1/lna)a^x + C,其中a > 0 且 a ≠ 15、∫ e^x dx = e^x + C6、∫ cosx dx = sinx + C7、∫ sinx dx = - cosx + C8、∫ cotx dx = ln|sinx| + C = - ln|cscx| + C9、∫ tanx dx = - ln|cosx| + C = ln|secx| + C10、∫ secx dx =ln|cot(x/2)| + C = (1/2)ln|(1 + sinx)/(1 - sinx)| + C = - ln|secx - tanx| + C = ln|secx + tanx| + C