For this case what you should do is:
1) Multiplication of terms within parentheses correctly.
2) Rewrite the expression respecting power properties.
3) Add or subtract terms of equal power.
Note: See attached image.
Answer:
x ^ 3 + 3x ^ 2 -16x - 48 = 0

8 0

4 years ago

Gary Oak is on a mission to complete his Pokedex before Ash Ketchum. To this end, he startssearching the tall grass for Pokemon.

bazaltina [42]

Answer:

Variance Σ i=1 (1 - Pi) /Pi^2

Expected value= π(1/1 + 1/2 .......... 1/n) = π.Hn

Step-by-step explanation:

From the information given, we can get

E(T) = E(t1) + E(t2) ......... +E(tn)

1/P1 + 1/P2.......... 1/Pn

-π/r + π/ r-1 +........... π/1

π(1/1 + 1/2 .......... 1/n)

To find the variance,

Variance= var (x1 + x2......... +xr)

E i=1 var (Xi)

Where,

x1, x2, x3 ........... are all independent of each other.

In case of xi : var (xi) = E(xi^2) - E(xi^2)

Probability of the ith term of coupon that would be observed

Pi = (n - i - 1)/n

Therefore,

i-1 coupons out of a total of n coupons.

To calculate Exi, probability Pi

The expected number of coupons required should be = 1

In probability, 1 - Pi expected number of coupons required E (Xi +1)

E(Xi) = Pi + (1- Pi) E(xi + 1)

E(Xi) = 1/Pi

Due to the above,

E(Xi)^2= Pi + (1- Pi) E(xi + 1)^2

E(Xi)^2= Pi + (1- Pi) E(xi^2 + 1 + 2xi)

E(Xi)^2= 2/Pi^2 - 1/Pi

Var (Xi) = 2/Pi^2 - 1/Pi - 1/Pi^2

= (1 - Pi) /Pi^2

Variance Σ i=1 (1 - Pi) /Pi^2

6 0

3 years ago