If the 3rd and 9th terms of an AP are 4 and -8, which term of this AP is zero?
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Step-by-step explanation:
a3=4
A9=-8
therefore
a+2d=4.............1
a+8d=-8...........2
subtracting 1 from 2
6d=-12
d=-2
in equation 1
a-4=4
a=8
according to condition
An=0
a+(n-1)d=0
8+(n-1)-2=0
n-1=4
n=5
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