Calculus
Critical points: x={−π3,0,π3}x=\(\left\]\lbrace\)-\(\frac{\pi}{3}\),0,\(\frac{\pi}{3}\[\right\]\rbrace\)
fmax(0)=3f_{\(\max\)}\(\left\)(0\(\right\))=3
fmin(−π3)=0f_{\(\min\)}\(\left\)(-\(\frac{\pi}{3}\]\right\))=0 and fmin(π3)=0f_{\(\min\)}\(\left\)(\(\frac{\pi}{3}\]\right\))=0
Critical points: x={−π3,0}x=\(\left\[\lbrace\)-\(\frac{\pi}{3}\),0\(\right\]\rbrace\)
fmax(0)=−1f_{\(\max\)}\(\left\)(0\(\right\))=-1
fmin(−π3)=−3f_{\(\min\)}\(\left\)(-\(\frac{\pi}{3}\]\right\))=-3 and fmin(π3)=−3f_{\(\min\)}\(\left\)(\(\frac{\pi}{3}\]\right\))=-3
fmax(π3)=−1f_{\(\max\)}\(\left\)(\(\frac{\pi}{3}\]\right\))=-1
fmin(−π3)=−3f_{\(\min\)}\(\left\)(-\(\frac{\pi}{3}\]\right\))=-3