### Home > CALC > Chapter 6 > Lesson 6.2.1 > Problem 6-63

This problem is asking you to find EXTREME VALUES on a closed domain.

Extreme values (global maxima and global minima) can exist where *y*' = 0 or where *y*' = DNE.

Find extrema candidates where *y*' = 0. Remember to only consider candidates within the given domain: [0, π].*y*' = 2cos*x* − 2sin*x* = 2(cos*x* − sin*x*)

0 = 2(cos*x* − sin*x*)

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Find more extrema candidates where *y*' = DNE. In other words, where is *y* non-differentiable? Are there endpoints, jumps, holes, cusps or vertical tangents? If so, these are extrema candidates. There are endpoint candidates at *x* = 0 and *x* = π.

3 extrema candidates have been identified.

Test each candidate to see who has the most extreme (highest and lowest) *y*-values.

The 'winners' are the global max and the global min.

*y*(0) = _________

*y*(π) = _________