Question 1098868
To find the stationary points, take the derivative and set it equal to zero.
{{{dy/dx=cos(x)-sin(x)=0}}}
{{{cos(x)=sin(x)}}}
{{{x=(1/4)pi}}}
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To find the inflection points, take the second derivative and set it equal to zero.
{{{d2y/dx2=-sin(x)-cos(x)=-(sin(x)+cos(x))=0}}}
{{{sin(x)=-cos(x)}}}
{{{x=(3/4)pi}}}