Question

calcule b = senx + cos(270° – x)

Answer 1

Hola !! ^^

b = sen (x) + cos (270° - x )

b = sen (x) - sen (x)

b = 0

Answer 2

Explicación paso a paso:

$\ sen \left(x\right)+\cos \left(270^{\circ \:}-x\right)$

Para resolver  $\cos \left(270^{\circ \:}-x\right)$ usamos la identidad trigonométrica para diferencia de ángulos:  $\cos \left(s-t\right)=\cos \left(s\right)\cos \left(t\right)+\ sen \left(s\right)\ sen \left(t\right)$

$=\cos \left(270^{\circ \:}\right)\cos \left(x\right)+\ sen \left(270^{\circ \:}\right)\ sen \left(x\right)$

$=0-\ sen \left(x\right)$

Seguimos:

$=\ sen \left(x\right)-\ sen \left(x\right)$

$=0.$