1.
If the function
f(x)={sin((k1+1)x)+sin((k21)x)x,x<04,x=02loge(2+x)x,x>0f(x) = \begin{cases} \frac{\sin((k_1+1)x) + \sin((k_2-1)x)}{x}, & x < 0 \\ 4, & x = 0 \\ \frac{2 - \log_e(2+x)}{x}, & x > 0 \end{cases}
is continuous at x=0x = 0, then k12+k22k_1^2 + k_2^2 is equal to