1.
Let f:R→Rf: \mathbb{R} \to \mathbb{R} be a function defined as

f(x)={asin⁡(π2(x+1))+sin⁡2x2x,x<0b,x=0tan⁡x−sin⁡xx3,x>0f(x) = \begin{cases} \frac{a \sin\left(\frac{\pi}{2}(x+1)\right) + \sin 2x}{2x}, & x < 0 \\ b, & x = 0 \\ \frac{\tan x - \sin x}{x^3}, & x > 0 \end{cases}


If ff is continuous at x=0x = 0, then the value of a+ba + b is equal to: