3 years ago

Calculate S (sub) 4 for the sequence defined by {a(sub)n}={19-4n}

Mathematics

1 answer:

Fudgin [204]3 years ago

7 0

Yup, you are correct

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Solve the equation for x.<br><br> 32(x − 8) = 14x + 3

Mademuasel [1]

x = 3 13/18. 3 13/18

5 0

2 years ago

Let r3 have the euclidean inner product. let u = (-1, 1, 1) and v = (-7, 6, 15). if ||ku + v||= 7, what is k? give the exact ans

amm1812

Ma $k\mathbf u+\mathbf v=k(-1,1,1)+(-7,6,15)=(-k-7,k+6,k+15)$

Recall that for a vector $\mathbf x\in\mathbb R^n$ , we have $\|\mathbf x\|=\sqrt{\mathbf x\cdot\mathbf x}$ . So we have

$\|k\mathbf u+\mathbf v\|=\sqrt{(k\mathbf u+\mathbf v)(k\mathbf u+\mathbf v)}=7$
$\implies k^2\mathbf u\cdot\mathbf u+2k\mathbf u\cdot\mathbf v+\mathbf v\cdot\mathbf v=49$
$\implies3k^2+56k+261=0$
$\implies k=-9,-\dfrac{29}3$