If f(x)=sinx and g(x)=cosx, what is the range of (f+g)(x)?
a) {y∈R∣0≤y≤1}
b) {y∈R∣−1≤y≤1}
c) {y∈R∣0≤y≤√2​}
d) {y∈R∣−√2​≤y≤√2​}