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4 years ago

If a = 9-4√5 find the value of a - 1/a

Mathematics

1 answer:

e-lub [12.9K]4 years ago

7 0

The solution is attached
the answer is -8√5

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Calcule ⁴√-16 por favor respondam

Elena-2011 [213]

Step-by-step explanation:

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Levi!!!!

6 0

3 years ago

Round place value of 2 in 234,890

nikklg [1K]

The two is in the ➡ hundred thousand

4 0

3 years ago

Fine length of BC on the following photo.

MrMuchimi

Answer:

$BC=4\sqrt{5}\ units$

Step-by-step explanation:

see the attached figure with letters to better understand the problem

step 1

In the right triangle ACD

Find the length side AC

Applying the Pythagorean Theorem

$AC^2=AD^2+DC^2$

substitute the given values

$AC^2=16^2+8^2$

$AC^2=320$

$AC=\sqrt{320}\ units$

simplify

$AC=8\sqrt{5}\ units$

step 2

In the right triangle ACD

Find the cosine of angle CAD

$cos(\angle CAD)=\frac{AD}{AC}$

substitute the given values

$cos(\angle CAD)=\frac{16}{8\sqrt{5}}$

$cos(\angle CAD)=\frac{2}{\sqrt{5}}$ ----> equation A

step 3

In the right triangle ABC

Find the cosine of angle BAC

$cos(\angle BAC)=\frac{AC}{AB}$

substitute the given values

$cos(\angle BAC)=\frac{8\sqrt{5}}{16+x}$ ----> equation B

step 4

Find the value of x

In this problem

$\angle CAD=\angle BAC$ ----> is the same angle

equate equation A and equation B

$\frac{8\sqrt{5}}{16+x}=\frac{2}{\sqrt{5}}$

solve for x

Multiply in cross

$(8\sqrt{5})(\sqrt{5})=(16+x)(2)\\\\40=32+2x\\\\2x=40-32\\\\2x=8\\\\x=4\ units$

$DB=4\ units$

step 5

Find the length of BC

In the right triangle BCD

Applying the Pythagorean Theorem

$BC^2=DC^2+DB^2$

substitute the given values

$BC^2=8^2+4^2$

$BC^2=80$

$BC=\sqrt{80}\ units$

simplify

$BC=4\sqrt{5}\ units$

7 0

3 years ago

Help me iv been trying from this morning

GalinKa [24]

Answer:

i did the first

Step-by-step explanation:

1st way

Standard form: a(X-h)²+k = ( -2/3X² -16/3X -32/3) +32/3 -17/3 = -2/3(X +4)² +5

y = -2/3*X^2-16/3*X-17/3

X = -4 ±√( 15/2) = -6.7386, or -1.2614

Axis of symmetry: X= -4; Vertex (maximum)=(h,k)=( -4, 5); y-intercept is (0,-5.66666666667)

two real roots: X=-1.2613872124776866 and -6.738612787477313

5 0

3 years ago

Read 2 more answers

There are 20 sixth graders and 25 seventh graders. If each group has the greatest possible number of club members, how many grou

seraphim [82]

4(5)=20
5(5)=25
4 groups of 6th grader
5 groups of 7th graders

6 0

3 years ago