Answer:
24 and 48
Today, the son is 24 years old, and the father is 48 years old.
Step-by-step explanation:
(x - 10) + (2x - 10) = 52
3x + 20 = 52
3x = 72
x = 24
The father is 2 times his son's age.
2x
= 2(24)
= 48
So, the son is 24 and the father is 48.
10 years ago, son was 14 and father was 38, if added, this adds up to 52, so we know our calculations are correct.
Answer:
16
Step-by-step explanation:
Given
f(x)=5x^2+9x-2
Remainder theorem states that when f(x) is divided by x-a then the remainder can be calculated by calculating f(a).
Now Using the remainder theorem to divide 5x^2+9x-2 by x+3 to find the remainder:
f(x)=5x^2+9x-2
f(-3) = 5(-3)^2 +9(-3) -2
=5(9) - 27 -2
= 45-29
= 16 !
Answer:

Step-by-step explanation:
Using the addition formulae for cosine
cos(x ± y) = cosxcosy ∓ sinxsiny
---------------------------------------------------------------
cos(120 + x) = cos120cosx - sin120sinx
= - cos60cosx - sin60sinx
= -
cosx -
sinx
squaring to obtain cos² (120 + x)
=
cos²x +
sinxcosx +
sin²x
--------------------------------------------------------------------
cos(120 - x) = cos120cosx + sin120sinx
= -cos60cosx + sin60sinx
= -
cosx +
sinx
squaring to obtain cos²(120 - x)
=
cos²x -
sinxcosx +
sin²x
--------------------------------------------------------------------------
Putting it all together
cos²x +
cos²x +
sinxcosx +
sin²x +
cos²x -
sinxcosx +
sin²x
= cos²x +
cos²x +
sin²x
=
cos²x +
sin²x
=
(cos²x + sin²x) = 
Yes. Any number that can be written as a fraction is defined as rational.