Ans
1
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dy/dx=tan$ and since $=0 [$ =0 coz tangent at maxima minima is parallel to x axis}
dy/dx=0
8 years ago
by
Meghansh Punjabi
Ans
2
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if you observe any graph except at end points you can easily observe at the point of maxima or minima graph is concave down /concave up ,for example take sin(x), the tangent is parallel to x axis , that shows that angle made by tangent with x axis i.e. inclination angle is zero , its simply shows that dy/dx is zero.
8 years ago
by
Gaurav Bhatt