the third term of a geometric sequence is t3= -75 and the sixth term is t6=9375. determine the first term and the common ratio.
how do I do this question I am trying really hard but I still don't comprehend this question!
the third term of a geometric sequence is t3= -75 and the sixth term is t6=9375. determine the first term and the common ratio.
how do I do this question I am trying really hard but I still don't comprehend this question!
If you write geometric sequences on a graph, they form lines...
Let us call the geometric term "x"
Let us call the value of the geometric term "y"
Now let's find the slope of that line...
The slope equation is:
Substitute:
Subtract:
Divide: (this is a very steep line)
All lines can be written in the form:
Substitute:
Multiply:
Subtract:
Go back to equation:
Substitute:
Substitute to find the first term:
Multiply:
Subtract:
but please, CHECK MY ARITHMETIC!!!!!!!!!!!!
Hello, frogsrcool!
The third term of a geometric sequence is and the sixth term is
Determine the first term and the common ratio.
You're expected to know that the term is: .
where is the first term and is the common ratio.
The term is -75: . [1]
The term is 9375: . [2]
Divide [2] by [1]: .
Substitute into [1]: .