Answer:
It's the law of cosines
Step-by-step explanation:
law of cosines states that 
so we know that a = 7, b = 4, and alpha would be 135 degrees, so just plugging it in gets us 49+16-2*7*4*(-0.707) = 65 + 39.59 = 104.59
Answer:
yes
Step-by-step explanation:
5678(1+(0.045×6))
5678=P as it is the principal amount
Answer:
Fast ball challenge
Step-by-step explanation:
Given
Slow Ball Challenge




Fast Ball Challenge




Required
Which should he choose?
To do this, we simply calculate the expected earnings of both.
Considering the slow ball challenge
First, we calculate the binomial probability that he hits all 7 pitches

Where
--- pitches
--- all hits
--- probability of hit
So, we have:




Using a calculator:
--- This is the probability that he wins
i.e.

The probability that he lose is:
---- Complement rule


The expected value is then calculated as:


Using a calculator, we have:
Considering the fast ball challenge
First, we calculate the binomial probability that he hits all 3 pitches

Where
--- pitches
--- all hits
--- probability of hit
So, we have:



Using a calculator:
--- This is the probability that he wins
i.e.

The probability that he lose is:
---- Complement rule


The expected value is then calculated as:


Using a calculator, we have:

So, we have:
-- Slow ball
--- Fast ball
<em>The expected earnings of the fast ball challenge is greater than that of the slow ball. Hence, he should choose the fast ball challenge.</em>
Answer:
The error is at step (3) .
The correct step (3) will be,

=
[by using the laws of indices]
All other steps are correct.
Step-by-step explanation:
The error is at the step (3) , because the student has tried to prove the quotient rule of logarithms by using the property i.e., 'The quotient rule of logarithm' itself , i.e. ,by assuming the property does hold before proving it. So, the proof is fallacious.
The correct step (3) will be,

=
[by using the laws of indices]
All other steps are correct.