r = 1/2
try that to get started.
The Product of three Consecutive terms of a G.P. is -64 and the first term is four times the third. find the number.
2 answers
3 numbers in gp when product is given is: a/r , a , ar .
Now ,
a/r ×a×ar= -64
=a^3=-64
=a= -4
Now it is given that first number is 4 times the third number so;
a/r=4(ar)
-4/r=4(-4r)
-1/r=-4r
1/4=r^2
r=+or-1/2
So we have a =-4 and r=+1/2 and -1/2 .
So we get no. as : a/r,a,ar....as
-8,-4,-2 or 8,-4,2
Now ,
a/r ×a×ar= -64
=a^3=-64
=a= -4
Now it is given that first number is 4 times the third number so;
a/r=4(ar)
-4/r=4(-4r)
-1/r=-4r
1/4=r^2
r=+or-1/2
So we have a =-4 and r=+1/2 and -1/2 .
So we get no. as : a/r,a,ar....as
-8,-4,-2 or 8,-4,2
2 answers