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3 years ago

Sammy wrote the following proof. What did he do wrong?

Mathematics

2 answers:

seraphim [82]3 years ago

8 0

i think it would be D i hope i helped

OLEGan [10]3 years ago

3 0

Answer:

Choice B is correct answer.

Step-by-step explanation:

We have given a expression.

cos²∅tan²∅

We have to simplify above expression.

Since, we know that

tan²∅ +1 = sec²∅

cos²∅tan²∅ = cos²∅(sec²∅-1)

cos²∅tan²∅ = cos²∅sec²∅-cos²∅

since, sec∅ is reciprocal of cos∅.

sec∅ = 1/cos∅

cos²∅tan²∅ = cos²∅(1/cos²∅)-cos²∅

cos²∅tan²∅ = 1-cos²∅

Since, from following equation;

cos²∅+sin²∅ = 1

cos²∅tan²∅ = sin²∅

Hence, choice B is the answer.

You might be interested in

Element X decays radioactively with a half-life of eight minutes. If there are 800 g of element X, how long, to the nearest 10th

Harman [31]

Answer: 41.5 min

Step-by-step explanation:

This problem can be solved with the Radioactive Half Life Formula:

$A=A_{o}.2^{\frac{-t}{h}}$ (1)

Where:

$A=22 g$ is the final amount of the radioactive element

$A_{o}=800 g$ is the initial amount of the radioactive element

$t$ is the time elapsed

$h=8 min$ is the half life of the radioactive element

So, we need to substitute the given values and find $t$ from (1):

$22 g=(800 g) 2^{\frac{-t}{8 min}}$ (2)

$\frac{22 g}{800 g}=2^{\frac{-t}{8 min}}$ (3)

$\frac{11}{400}=2^{\frac{-t}{8 min}}$ (4)

Applying natural logarithm in both sides:

$ln(\frac{11}{400})=ln(2^{\frac{-t}{8 min}})$ (5)

$-3.593=-\frac{t}{8 min}ln(2)$ (6)

Clearing $t$ :

$t=41.46 min \approx 41.5 min$ This is the time elapsed

7 0

3 years ago

Madison works as a salesperson at an electronics store and sells phones and phone accessories, and makes a fixed commission for

Jet001 [13]

Answer:

Price of each phone: $\$9$

Price of each accessory: $\$3.5$

Step-by-step explanation:

Let be "p" the price in dollars of each phone and "a" the price in dollars of each accessory.

Set up a system of equations:

$\left \{ {{8p+10a=107} \atop {4p+23a=116.50}} \right.$

You can use the Elimination Method to solve the system.

Multiply the second equation by -2 and add both equations:

$\left \{ {{8p+10a=107} \atop {-8p-46a=-233}} \right.\\............................\\-36a=-126\\\\a=\frac{-126}{-36}\\\\a=3.5$

Substitute the value of "a" into the first equation and solve for "p":

$8p+10(3.5)=107\\\\8p=107-35\\\\p=\frac{72}{8}\\\\p=9$

4 0

4 years ago

1/5,0,-1/5,what two answers comes next?

jenyasd209 [6]

The next 2 answers are: -2/5 and -3/5

4 0

3 years ago

What is 6000 minus 3672?

Kamila [148]

6000 - 3672 = 2328

Just use a calculator my friend :)

8 0

3 years ago

Read 2 more answers

Find f(3x-2) for f(x)=x-5

serious [3.7K]

Answer:

f(x)=x–5

f (3x–2) = (3x–2) –5

f (3x–2) = 3x–7

I hope I helped you^_^

4 0

3 years ago