Question

f(x) = x - 2cosx
f(-π) =?

Answer 1

$heya \\ \\ \cos( - \alpha ) = \cos( \alpha ) \\ \\ \\ f( - \pi) = ( - \pi) - 2 \cos( - \pi) \\ \\ f( - \pi) = - \pi - 2( - 1) \\ \\ f( - \pi) = - \pi + 2 \\ \\ \\ have \: a \: nyc \: tym$

Answer 2

f(x) = x - 2cosx
f(-π) = -π -2 cos(-π)
= -π - 2cos(π) because cos(-π) = cos(π)= -1
= -π -2(-1)
= -π+2
= w-π

I hope it helps