Statistical functions to calculate exponential trendline

[ray78]

Hi, I am relatively new to app sheet. Would like to know if there is a way to calculate exponential trendline for values in a table based on conditions.

Basically, to obtain results fm the equation : y =aEXP(bx) where
a: =EXP(INDEX(LINEST(LN(y), x), 1, 2))

b: =INDEX(LINEST(LN(y), x), 1)