We know that sin2x=2sinxcosx
(search the net for proof if you wish)
So the original equation becomes
2sinxcosx-sinx=0
The two terms both have sinx that can be taken out to get:
sinx(2cosx-1)=0
This is true if sinx=0 or 2cosx-1=0 , rewritten: cosx=1/2
sinx=0 than x=2kπ
cosx=1/2 than x=π/3+2kπ
where k is an integer
A number that has a decimal that does not repeat or end in an irrational number. The decimal goes on forever, without a pattern. Think of it as it is irrational to keep going on and on and on. Irrational numbers also cannot be put into fractions.
-5 is an integer, it is a whole (positive or negative without a decimal/fraction) number. An integer can be any whole number as long as it is a whole number and does not have a decimal.<span />
Answer:
B. √21
Step-by-step explanation:
x^2 = √5 x √5 + 4 x 4
x^2 = 5 + 16
x^2 = 21
x = √21
<em>Hope that helps! :)</em>
<em></em>
<em>-Aphrodite</em>
The image is missing so i have attached it.
Answer:
Volume = 1.5 litres
Step-by-step explanation:
Using pythagoras theorem, we can get the height (h) of the cylinder
14² + h² = 17²
h² = 289 - 196
h = √93
Now, volume of a cylinder is;
V = πr²h
In the image, r = diameter/2 = 14/2 = 7cm
Thus,
V = π × 7² × √93
V = 1485 cm³
Now, 1 litre = 1000 cm³
Thus, volume = 1485/1000 = 1.485 litres ≈ 1.5 litres
Answer:
1) 25
2) 2
3) f(g(1)) = 42
Step-by-step explanation:
1) Given that f(x) = 4x^2 + 9
If x = -2
f(-2) = 4(-2)^2 + 9
f(-2) = 4(4) + 9
f(-2) = 16 + 9
f(-2) = 25
2) Given that f(x) = 4x - 6
y = 4x - 6
Replace y with x
x = 4y - 6
MAke y the subject of the forfmula
4y = x+ 6
y = (x+6)/4
SInce x = 2
f^(-1)(2) = (2+6)/4
f^(-1)(2) = 8/4 = 2
3) If f(x) = 6x and g(x) = x+6
f(g(x)) = f(x+6)
f(x+6) = 6(x+6)
Since x = 1
f(g(1)) = 6(1+6)
f(g(1)) = 6(7)
f(g(1)) = 42
