First find how many were deleted, by subtracting the remaining amount from the original amount:
215 - 129 = 86 pictures deleted.
Now divide the amount deleted by the original amount:
86 / 215 = 0.4
Multiply by 100:
0.4 x 100 = 40%
There was a 40% decrease.
Use the double angle identity:
sin(2<em>x</em>) = 2 sin(<em>x</em>) cos(<em>x</em>)
Now rewrite
sin(2<em>x</em>) sin(<em>x</em>) + cos(<em>x</em>) = 0
as
2 sin²(<em>x</em>) cos(<em>x</em>) + cos(<em>x</em>) = 0
Factor out cos(<em>x</em>) :
cos(<em>x</em>) (2 sin²(<em>x</em>) + 1) = 0
Consider the two cases,
cos(<em>x</em>) = 0 OR 2 sin²(<em>x</em>) + 1 = 0
Solve for cos(<em>x</em>) and sin²(<em>x</em>) :
cos(<em>x</em>) = 0 OR sin²(<em>x</em>) = -1/2
Squaring a real number always gives a non-negative number, so the second case doesn't offer any real solutions. We're left with
cos(<em>x</em>) = 0
Cosine is zero for odd multiples of <em>π</em>/2, so we have
<em>x</em> = (2<em>n</em> + 1) <em>π</em>/2
where <em>n</em> is any integer.
The velocity or speed of the kayaker going north at a speed of 3 m/s and that of the current going east at a speed of 2 m/s create a resultant speed of √13 m/s. The new distance that has to be traveled by the kayaker in order to move 100 m north is calculated through the equation,
3 / √13 = 100 / x
The value of x is 120 m. The total time it will take for the kayaker to reach the destination is,
t = 120 / √13 = 33.33 s
Answer:
Step-by-step explanation:
Let x represent original price of an item.
We have been given that sales tax is 8.5%. The cost of item after sales tax would be x plus 8.5% of x.
Therefore, our required expression would be .
Answer:
The correct option is C
Step-by-step explanation:
From the question we are told that
The number of independent variables is
The number of observation is
Since n is are independent variables then their degree of freedom is 3
The denominator(i.e z) degrees of freedom is evaluated as
So for the numerator (n) the degree of freedom is Df(n) = 3
So for the denominator(i.e z) the degree of freedom is Df(z) = 43