问题
选择题
函数f(x)=excosx的图象在点(0,f(0))处的切线倾斜角的余弦值为( )
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答案
由题意得,f′(x)=excosx-exsinx,
∴在点(0,f(0))处的切线的斜率是:
f′(0)=e0cos0-e0sin0=1,
∴在点(0,f(0))处的切线倾斜角是:45°,
则倾斜角的余弦值是:
,2 2
故选C.
函数f(x)=excosx的图象在点(0,f(0))处的切线倾斜角的余弦值为( )
|
由题意得,f′(x)=excosx-exsinx,
∴在点(0,f(0))处的切线的斜率是:
f′(0)=e0cos0-e0sin0=1,
∴在点(0,f(0))处的切线倾斜角是:45°,
则倾斜角的余弦值是:
,2 2
故选C.