Which term of the sequence 114, 109, 104 .... is the first negative term ?
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a = 114
d = -5
n = ?
an < 0
an = a + (n-1)(d)
a + (n-1)(d) < 0
114 + (n-1)(-5) < 0
114 - 5n + 5 < 0
119 - 5n < 0
119 = 5n
n = 119/5 = 23.8
So the first negative term of the A.P. will be its 24th term
Verification
an = a + (n-1)(d)
a24 = 114 + ( 24 - 1 ) ( -5 )
a24 = 114 - 115
a24 = -1
d = -5
n = ?
an < 0
an = a + (n-1)(d)
a + (n-1)(d) < 0
114 + (n-1)(-5) < 0
114 - 5n + 5 < 0
119 - 5n < 0
119 = 5n
n = 119/5 = 23.8
So the first negative term of the A.P. will be its 24th term
Verification
an = a + (n-1)(d)
a24 = 114 + ( 24 - 1 ) ( -5 )
a24 = 114 - 115
a24 = -1
honeyaman4561:
an kaisa < 0 hoga
< 0
less than 0
Negative no. 0 se chhote hote h toh an < 0
ok
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