find the amount on rupees 4000 in 2 years if the rate of interest for the first year it is 10% and for the second year is 15%
Answers
Answer:
interest of first year= 800 and interest of second year=. 1200
Step-by-step explanation:
rupees 4000
rate of first year- 10%
rate of second year- 15%
l=p×r×n
amount of first year- 4000×10×2/100
:. 80000/100
:. rupees 800 for first year
:. amount of second year-4000×15×2/100
:.1,20,000/100
:.1200rupees for second year
total interest = 2000 ₹
Answer:
Step-by-step explanation:
f(x) = kx³ – 8x² + 5
Roots are α – β , α & α +β
Sum of roots = – (-8)/k
Sum of roots = α – β + α + α +β = 3α
= 3α = 8/k
= k = 8/3α
or we can solve as below
f(x) = (x – (α – β)(x – α)(x – (α +β))
= (x – α)(x² – x(α+β + α – β) + (α² – β²))
= (x – α)(x² – 2xα + (α² – β²))
= x³ – 2x²α + x(α² – β²) – αx² +2α²x – α³ + αβ²
= x³ – 3αx² + x(3α² – β²) + αβ² – α³
= kx³ – 3αkx² + xk(3α² – β²) + k(αβ² – α³)
comparing with
kx³ – 8x² + 5
k(3α² – β²) = 0 => 3α² = β²
k(αβ² – α³) = 5
=k(3α³ – α³) = 5
= k2α³ = 5
3αk = 8 => k = 8/3α
(8/3α)2α³ = 5
=> α² = 15/16
=> α = √15 / 4