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3 years ago

If ln(x^2-x-1)=0 , then x= ?

Mathematics

1 answer:

Umnica [9.8K]3 years ago

3 0

Answer:

x = -1 or 2

Step-by-step explanation:

Taking the antilog, you have the quadratic ...

x^2 -x -1 = 1

x^2 -x -2 = 0 . . . . subtract 1

(x -2)(x +1) = 0 . . . factor

The values of x that make these factors zero are the solutions to the equation.

x = 2 or x = -1

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Vladimir79 [104]

I think it’s a positive

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2 years ago

What value is x. -2(3x+2)>-8x+6

givi [52]

Step-by-step explanation:

-6x - 4 > 8x + 6

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3 years ago

Solve

PIT_PIT [208]

A cylinder of radius r cm and height h cm has a curved surface area A cm². Where –

A = 2πrh cm²

a) We are asked to find formula for h.

$\qquad$ $\purple{ \bf \longrightarrow A=2 \pi rh }$

First, overturn the equation

$\qquad$ $\sf \longrightarrow 2 \pi rh =A$

Divide both sides by 2πr

$\qquad$ $\sf \longrightarrow \dfrac{2\pi rh}{2\pi r } = \dfrac{A}{2\pi r}$

$\qquad$ $\sf \longrightarrow \dfrac{\cancel{2 \pi r }h}{\cancel{2\pi r} } = \dfrac{A}{2\pi r}$

$\qquad$ $\purple{\bf \longrightarrow h = \dfrac{A}{2 \pi r }}$

b) Again, we are given –

Curved surface area, A = 93 cm²
Radius, r = 2.5 cm
π = 3.1

$\qquad\qquad\quad\underline{\sf{Substituting \ Values \ :}}$

⠀⠀⠀━━━━━━━━━━━━━━━━━━━━━━━━━━

$\qquad$ $\bf \longrightarrow h = \dfrac{A}{2\pi r }$

$\qquad$ $\sf \longrightarrow h = \dfrac{93}{2 \times 3.1 \times 2.5 }$

$\qquad$ $\sf \longrightarrow h = \dfrac{93}{15.5}$

$\qquad$ $\sf \longrightarrow h =\cancel{ \dfrac{93}{15.5}}$

$\qquad$ $\pink{ \bf \longrightarrow h = 6\: cm }$

Henceforth, height of the cylinder is 6 cm.

5 0

2 years ago

Read 2 more answers

Help asap pleaseeee !!!!!!

natima [27]

Answer:

C. ⅓ × (8 + 7) + 12

Step-by-step explanation:

Let's translate each statement given to numerals and symbols first:

Twelve => 12

One-third => ⅓

Sum of 8 and 7 => (8 + 7)

Representing this statement altogether will be:

⅓ of (8 + 7) = ⅓ × (8 + 7)

If 13 is added, we would get:

⅓ × (8 + 7) + 12

8 0

3 years ago

Calculus1 help involving graphs.

tatuchka [14]

Answer:

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Step-by-step explanation:

Pick two points on the tangent line, and find the slope between them.

The line passes through approximately (30,145) and (90, 105).

m = (105 − 145) / (90 − 30)

m = -0.67

4 0

3 years ago