1. The problem statement, all variables and given/known data For which values of a E ℝ, is the function given by f(x) = pieceise function x^2+4x-4, x<a cos((x-a)/2) , x ≥ a. continuous at x=a 2. Relevant equations I'm getting stuck on the algebra part to be honest. 3. The attempt at a solution lim x→a f(x)= f(a) to be continuous lim x→a- = x^2+4x-4 and this must be equal to lim x→a+ = cos((x-a)/2) I think its 1 because cos(1-1/2)=1 and 1+4-4=1 I'm just confused on the working out part, how to I algebraically manipulate the equations to show this? or am I completely wrong. thanks in advance.