Question

9, 4, –1, –6 ......... या अंकगणिती श्रेढीसाठी t₁₉ = ? 

कृती: येथे, a = 9, d = `square`

t_n = a + (n –1)d

t₁₉ = 9 + (19 –1) `square`

= 9 + `square`

= `square`

Answer 1

येथे, a = 9, d = 4 - 9 = -5

t_n = a + (n –1)d 

t₁₉ = 9 + (19 –1) -5

= 9 + 18(– 5) 

= 9 + (-90) 

= -81