“微信扫一扫”进入题库练习及模拟考试
下列说法中正确的有( )
A.\({\left( {\sin \frac{\pi }{4}} \right)^\prime } = \cos \frac{\pi }{4}\).
B.已知函数\(f\left ( {x} \right )\)在\(\text{R}\)上可导,且\(f'(1) = 1\),则\(\mathop {\lim }\limits_{\Delta x \to 0} \frac{{f(1 + 2\Delta x) - f(1)}}{{\Delta x}} = 2\).
C.一质点的运动方程为\(S = {t^2}\),则该质点在\(t = 2\)时的瞬时速度是4.
D.已知函数\(f(x) = \cos x\),则函数\(y = {f^\prime }(x)\)的图象关于原点对称.
参考答案:BCD