Answer:
See below.
Step-by-step explanation:
I will assume that 3n is the last term.
First let n = k, then:
Sum ( k terms) = 7k^2 + 3k
Now, the sum of k+1 terms = 7k^2 + 3k + (k+1) th term
= 7k^2 + 3k + 14(k + 1) - 4
= 7k^2 + 17k + 10
Now 7(k + 1)^2 = 7k^2 +14 k + 7 so
7k^2 + 17k + 10
= 7(k + 1)^2 + 3k + 3
= 7(k + 1)^2 + 3(k + 1)
Which is the formula for the Sum of k terms with the k replaced by k + 1.
Therefore we can say if the sum formula is true for k terms then it is also true for (k + 1) terms.
But the formula is true for 1 term because 7(1)^2 + 3(1) = 10 .
So it must also be true for all subsequent( 2,3 etc) terms.
This completes the proof.
Answer:
See below.
Step-by-step explanation:
x^2 + 2 = 3^2/3 + 3^-2/3
x^2 = 3^2/3 + 3^-2/3 - 2
x = √(3^2/3 + 3^-2/3 - 2)
x = 0.748888296
Substitute for x in 3x^3 + 9x - 8:
3( 0.748888296)^3 + 9( 0.748888296) - 8 = 0.
So it is proved.
Answer:
Step-by-step explanation:
at the center of it's gravity
