1) To find the value of y when x = π/3 for the equation y = -cosx + 2:

y = -cos$\pi /3$ + 2
y = -$1/2$ + 2
y = 2 - 1/2
y = 1.5

Therefore, when x = π/3, y = 1.5.

2) To find the value of y when x = -π/4 for the equation y = tanx + 4:

y = tan$-\pi /4$ + 4
y = -1 + 4
y = 3

Therefore, when x = -π/4, y = 3.