All categories

3 years ago

Please help me with logarithms!

Mathematics

2 answers:

Dmitry [639]3 years ago

3 0

Answer:

x=2ln(2)/(2ln(2)-ln(3))

Step-by-step explanation:

ln(4^x-1)=ln(3^x)

(x-1)ln(4)=ln(3^x)

(x-1)ln(4)=xln(3)

ln(4)x-ln(4)=xln(3)

ln(4)x=ln(3)x+2ln(2)

2ln(2)x-ln(3)x=2ln(2)

(2ln(2)-ln(3))x=2ln(2)

Therefore, x=2ln(2)/(2ln(2)-ln(3))

Liula [17]3 years ago

3 0

Answer:

4.819 =x

Step-by-step explanation:

4^(x-1) = 3^x

Take the log of each side

log (4^(x-1)) = log(3^x)

We know that log a^b = blog a

(x-1) log 4 = x log (3)

Distribute

x log 4 -log 4 = x log 3

Subtract x log 4 from each side

x log 4 - x log 4 -log 4 = x log 3 - x log 4

- log 4 = x log 3 - x log 4

Factor out -x

- log 4 =- x ( log 4- log 3)

Divide by -1

log 4 = x (log 4 - log 3)

Divide each side by (log 4 - log 3)

log 4 / (log 4 - log 3) = x

4.81884167930641800 =x

Round to the nearest thousandth

4.819 =x

You might be interested in

Find the measure of A A:46 B:90 C:134 D:88

grigory [225]

Answer:

Option d = 88

Step-by-step explanation:

Angle c = 46 degrees

46 + 46 = 92

180 - 92 = 88

5 0

3 years ago

Read 2 more answers

Solve the following equation: 8 - 9x = 27.

bearhunter [10]

The given equation is

$8-9x=27$

To solve for x, we have to subtract 8 to both sides

$8-9x-9 = 27-8 \\ -9x = 19$

Now we need to get rid of -9 from the left side, and for that we do division

$\frac{-9x}{-9} = \frac{19}{-9}$

$x = - \frac{19}{9}$

4 0

3 years ago

The vertices of a parallelogram are A(x1, y1), B(x2, y2), C(x3, y3), and D(x4, y4). Which of the following must be true if paral

Iteru [2.4K]

The answer is really none of the above, because all of these have divisions by difference in x, and there are perfectly fine rectangles where those will mean dividing by zero.

To do the problem the way they want us to, we note segments with the same slope are parallel (or collinear); segments with slopes which multiply to -1 are perpendicular.

Let's figure out what each choice is trying to tell us by translating it into parallel and perpendicular. Remember A is point 1, ...

A. ((y_4-y_3)/(x_4-x_3)= (y_3-y_2)/(x_3-x_2)) and ((y_4-y_3)/(x_4-x_3)×(y_3-y_2)/(x_3-x_2))=-1

translated, that's CD║BC and CD⊥BC - contradictory; second half right

B. (y_4-y_3)/(x_4-x_3)= (y_2-y_1)/(x_2-x_1) and ((y_4-y_3)/(x_4-x_3)×(y_2-y_1)/(x_2-x_1))=-1

CD ║ AB and CD ⊥ AB - only the parallelogram half is right

C. (y_4-y_3)/(x_4-x_3)= (y_2-y_1)/(x_2-x_1) and (y_4-y_3)/(x_4-x_3)×(y_3-y_2)/(x_3-x_2)=-1

CD║AB and CD⊥BC - that's TRUE

D. (y_4-y_3)/(x_4-x_3)= (y_3-y_1)/(x_3-x_1) and (y_4-y_3)/(x_4-x_3)×(y_2-y_1)/(x_2-x_1)=-1

CD║AC and CD⊥AB - nope

Answer: C

The way I'd get the proper expression is with the dot product.

A parallelogram is a rectangle when adjacent sides are perpendicular. It only takes one right angle to make them all right.

Two sides are perpendicular when the dot product of their direction vectors is zero. All the answers have $y_4 - y_3$ so one side is CD. The other side must be BC or AD; AD would give $y_4 - y_1$ terms which don't appear among the answer, so let's go with BC.