Law of cosines
:
The law of cosines establishes:

general guidelines:
The law of cosines is used to find the missing parts of an oblique triangle (not rectangle) when either the two-sided measurements and the included angle measure are known (SAS) or the lengths of the three sides (SSS) are known.
Law of the sines:
In ΔABC is an oblique triangle with sides a, b, and c, then:

The law of the sines is the relation between the sides and angles of triangles not rectangles (obliques). It simply states that the ratio of the length of one side of a triangle to the sine of the angle opposite to that side is equal for all sides and angles in a given triangle.
General guidelines:
To use the law of the sines you need to know either two angles and one side of the triangle (AAS or ASA) or two sides and an opposite angle of one of them (SSA).
The ambiguous case
:
If two sides and an angle opposite one of them is given, three possibilities may occur.
(1) The triangle does not exist.
(2) Two different triangles exist.
(3) Exactly a triangle exists.
If we are given two sides and an included angle of a triangle or if we are given 3 sides of a triangle, we can not use the law of the sines because we can not establish any proportion where sufficient information is known. In these two cases we must use the law of cosines
36×0.25=9 and 9÷3=6. So 6 apples are left after making these desserts.
Answer:
The required vector parametric equation is given as:
r(t) = <3cost, 3sint>
For 0 ≤ t ≤ 2π
Step-by-step explanation:
Given that
f(x, y) = <2y, -sin(y)>
Since C is a cirlce centered at the origin (0, 0), with radius r = 3, it takes the form
(x - 0)² + (y - 0)² = r²
Which is
x² + y² = 9
Because
cos²β + sin²β = 1
and we want to find a vector parametric equations r(t) for the circle C that starts at the point (3, 0), we can write
x = 3cosβ
y = 3sinβ
So that
x² + y² = 3²cos²β + 3²sin²β
= 9(cos²β + sin²β) = 9
That is
x² + y² = 9
The vector parametric equation r(t) is therefore given as
r(t) = <x(t), y(t)>
= <3cost, 3sint>
For 0 ≤ t ≤ 2π
In this equation, you have to treat the number in the bracket first on the basis of BODMAS
15 - [-3]- 4
Note that when two minuses come together the product is a plus sign.
15 +3 - 4
You have to add before you subract
18 - 4 =14
Therefore, 15- [-3] - 4 = 14.