∫secx dx=?∫secx dx=∫(dx)/cosx=∫(cosx/cos²x)dx =∫(d sinx)/(1-sin²x) =(1/2)ln│(1+sinx)/(1-sinx)│+C =(1/2)ln(1+sinx)²/(1-sin²x)+C =(1/2)ln[(1+sinx)/cosx]²+C =ln│secx+tanx

来源:学生作业帮助网 编辑:作业帮 时间:2024/04/28 14:54:23
∫secx dx=?∫secx dx=∫(dx)/cosx=∫(cosx/cos²x)dx         =∫(d sinx)/(1-sin²x)         =(1/2)ln│(1+sinx)/(1-sinx)│+C         =(1/2)ln(1+sinx)²/(1-sin²x)+C         =(1/2)ln[(1+sinx)/cosx]²+C         =ln│secx+tanx

∫secx dx=?∫secx dx=∫(dx)/cosx=∫(cosx/cos²x)dx =∫(d sinx)/(1-sin²x) =(1/2)ln│(1+sinx)/(1-sinx)│+C =(1/2)ln(1+sinx)²/(1-sin²x)+C =(1/2)ln[(1+sinx)/cosx]²+C =ln│secx+tanx
∫secx dx=?
∫secx dx=∫(dx)/cosx=∫(cosx/cos²x)dx
=∫(d sinx)/(1-sin²x)
=(1/2)ln│(1+sinx)/(1-sinx)│+C
=(1/2)ln(1+sinx)²/(1-sin²x)+C
=(1/2)ln[(1+sinx)/cosx]²+C
=ln│secx+tanx│+C
从这一步开始=(1/2)ln│(1+sinx)/(1-sinx)│+C
又取消绝对值符号,后面又加上绝对值符号是什么意思呀?
为什么要这样一会取消一会加上的,我不能理解,请指点

∫secx dx=?∫secx dx=∫(dx)/cosx=∫(cosx/cos²x)dx =∫(d sinx)/(1-sin²x) =(1/2)ln│(1+sinx)/(1-sinx)│+C =(1/2)ln(1+sinx)²/(1-sin²x)+C =(1/2)ln[(1+sinx)/cosx]²+C =ln│secx+tanx
=(1/2)ln│(1+sinx)/(1-sinx)│+C这一步必须要绝对值保证里面为正,而同时乘以一个(1+sinx)上面是个平方绝对为正,下面sin²x

这不用往下化了
微积分公式就到此了
正割的积分就这。
你不用再通分了

∫secxdx
=∫sec²x/secxdx
=∫cosx/cos²xdx
=∫1/cos²xdsinx
=∫1/(1-sin²x)dsinx
=-∫1/(sinx+1)(sinx-1)dsinx
=-∫[1/(sinx-1)-1/(sinx+1)]/2dsinx
=-[∫1/(sinx-1)dsinx...

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∫secxdx
=∫sec²x/secxdx
=∫cosx/cos²xdx
=∫1/cos²xdsinx
=∫1/(1-sin²x)dsinx
=-∫1/(sinx+1)(sinx-1)dsinx
=-∫[1/(sinx-1)-1/(sinx+1)]/2dsinx
=-[∫1/(sinx-1)dsinx-∫1/(sinx+1)dsinx]/2
=[∫1/(sinx+1)d(sinx+1)-∫1/(sinx-1)d(sinx-1)]/2
=(ln|sinx+1|-ln|sinx-1|)/2+C
=ln√|(sinx+1)/(sinx-1)|+C
=ln√|(sinx+1)²/(sinx+1)(sinx-1)|+C
=ln√|(sinx+1)²/(sin²x-1)|+C
=ln√|-(sinx+1)²/cos²x|+C
=ln|(sinx+1)/cosx|+C
=ln|tanx+1/cosx|+C
=ln|secx+tanx|+C

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