# Geometric seq

Find the third member of geometric progression if a1 + a2 = 36 and a1 + a3 = 90. Calculate its quotient.

Result

c1 =  81
c2 =  373248
q1 =  3
q2 =  -0.5

#### Solution:

Checkout calculation with our calculator of quadratic equations.

Leave us a comment of example and its solution (i.e. if it is still somewhat unclear...):

Be the first to comment!

#### To solve this example are needed these knowledge from mathematics:

Looking for help with calculating roots of a quadratic equation? Do you have a system of equations and looking for calculator system of linear equations?

## Next similar examples:

1. Six terms
Find the first six terms of the sequence a1 = -3, an = 2 * an-1
2. Geometric sequence 5
About members of geometric sequence we know: ? ? Calculate a1 (first member) and q (common ratio or q-coefficient)
3. GP members
The geometric sequence has 10 members. The last two members are 2 and -1. Which member is -1/16?
4. Geometric progression 2
There is geometric sequence with a1=5.7 and quotient q=-2.5. Calculate a17.
5. Coefficient
Determine the coefficient of this sequence: 7.2; 2.4; 0.8
6. A perineum
A perineum string is 10% shorter than its original string. The first string is 24, what is the 9th string or term?
Find the roots of the quadratic equation: 3x2-4x + (-4) = 0.
8. Evaluation of expressions
If a2-3a+1=0, find (i)a2+1/a2 (ii) a3+1/a3
9. Algebra
X+y=5, find xy (find the product of x and y if x+y = 5)
10. Expression with powers
If x-1/x=5, find the value of x4+1/x4
11. Roots
Determine the quadratic equation absolute coefficient q, that the equation has a real double root and the root x calculate: ?
12. Equation
Equation ? has one root x1 = 8. Determine the coefficient b and the second root x2.
13. Discriminant
Determine the discriminant of the equation: ?
14. Expressions 3
If k(x+6)= 4x2 + 20, what is k(10)=?
15. Square root 2
If the square root of 3m2 +22 and -x = 0, and x=7, what is m?
16. Theorem prove
We want to prove the sentense: If the natural number n is divisible by six, then n is divisible by three. From what assumption we started?
17. Linsys2
Solve two equations with two unknowns: 400x+120y=147.2 350x+200y=144