integral of (1+cos(x))/(cos^2(x))

解

\int \frac{1 + cos ( x )}{cos ^{2} ( x )} d x

tan (x) + ln ∣ tan (x) + sec (x) ∣ + C

解答ステップ

\int \frac{1 + cos ( x )}{cos ^{2} ( x )} d x

拡張

\frac{1 + cos ( x )}{cos ^{2} ( x )} : \frac{1}{cos ^{2} ( x )} + \frac{1}{cos ( x )}

= \int \frac{1}{cos ^{2} ( x )} + \frac{1}{cos ( x )} d x

総和規則を適用する:

\int f (x) \pm g (x) d x = \int f (x) d x \pm \int g (x) d x

= \int \frac{1}{cos ^{2} ( x )} d x + \int \frac{1}{cos ( x )} d x

\int \frac{1}{cos ^{2} ( x )} d x = tan (x)

\int \frac{1}{cos ( x )} d x = ln ∣ tan (x) + sec (x) ∣

= tan (x) + ln ∣ tan (x) + sec (x) ∣

定数を解答に追加する

= tan (x) + ln ∣ tan (x) + sec (x) ∣ + C