Answer: A
<u>Step-by-step explanation:</u>
f(x) = x³ + 4x² + 7x + 6
possible rational roots are ±{1, 2, 3, 6}
Try x = -2
-2 | 1 4 7 6
<u>| ↓ -2 -4 -6</u>
1 2 3 0 ← remainder is 0 so x = -2 is a root ⇒ (x + 2) = 0
The factored polynomial x² + 2x + 3 = 0 is not factorable so use the quadratic formula to find the roots.
a=1, b=2, c=3
The factors are:
![(x - 2)[x - (-1 + i\sqrt{2})][x - (-1 - i\sqrt{2})]](https://tex.z-dn.net/?f=%28x%20-%202%29%5Bx%20-%20%28-1%20%2B%20i%5Csqrt%7B2%7D%29%5D%5Bx%20-%20%28-1%20-%20i%5Csqrt%7B2%7D%29%5D)
When Peter does this, he is creating two sides of a right-angle triangle. The distance from his house to that point will be the hypotenuse of the triangle thus, to work out the length of the hypotenuse, we have to use Pythagoras Theorem! So:
a² + b² = c²
15² + 15² = c²
225 + 225 = c²
450 = c²
15√2 = c
21.21320344 = c
So, this rounded to the nearest tenth would be:
21.2 meters !
Answer:
A
Step-by-step explanation:It Said on Usa Test prep
Answer:
n = 60.22
Step-by-step explanation:
Hello
To find Sn, we need to draw out equations for each a₇ and a₁₉
In an arithmetic progression,
Sn = a + (n-1)d
Where Sn = sum of the A.P
a = first term
d = common difference
a₇ = 32
32 = a + (7-1)d
32 = a + 6d ........equation (i)
a₁₉ = 140
140 = a + (19-1)d
140 = a + 18d .........equation (ii)
Solve equation (i) and (ii) simultaneously
From equation (i)
32 = a + 6d
Make a the subject of formula
a = 32 - 6d .....equation (iii)
Put equation (iii) into equation (ii)
140 = (32 - 6d) + 18d
140 = 32 - 6d + 18d
Collect like terms
140 - 32 = 12d
12d = 108
d = 108 / 12
d = 9
Put d = 9 in equation (i)
32 = a + 6(9)
32 = a + 54
a = 32 - 54
a = -22
When Sn = 511
Sn = a + (n - 1)d
Substitute and solve for n
511 = -22 + (n-1) × 9
511 = -22 + 9n - 9
511 = -31 + 9n
511 + 31 = 9n
542 = 9n
n = 542 / 9
n = 60.22
Answer: 9823
Step-by-step explanation:
