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It is a mathematical equation that allows you to "solve" a triangle (find all length and angle values), if you know 2 sides and an included angle, or all three sides. It doesn't have to be a right triangle. You can find the cosine on a calculator easily.
c2 = a2 + b2- 2ab cos C
C = included angle
c = side opposite angle C (c)
a = side a
b = side b
The cosine law relates the length of the sides of a triangle to one of the angles in the triangle. If the triangle is labelled with vertices A, B, C with usual notation for edges (ie a is the side opposite the vertex A, so not touching A) and if x is the angle at vertex C then the cosine law says (c^2)=(a^2)+(b^2)-2abcos(x)
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When you have a right angle what does the law of cosines reduce to?
cosine = adjacent/hypotenuse
What are the formulas for law of sines and law of cosines?
sine: sin(A) sin(B) sin(C) cosines: a2=b2+c2-2bc cos(A).........----- = ----- = ------........,,,.a .......b........ ca is side BC A is angle A sin(A) means sine of angle Apsst, theres a law of tangents too, but its so complicated that im not gonna post it hereLaw of sine -A B C------ = ------ = ------Sin(a) Sin(b) Sin(c)
Topics need for trigonometry?
There are several topics under the broad category of trigonometry. * Angle measurements * Properties of angles and circles * Basic trigonometric functions and their reciprocals and co-functions * Graphs of trigonometric functions * Trigonometric identities * Angle addition and subtraction formulas for trigonometric functions * Double and half angle formulas for trigonometric functions * Law of sines and law of cosines * Polar and polar imaginary coordinates.
Sine and cosine of real numbers?
Putting a question mark at the end of a phrase does not make it a sensible of even an answerable question. Sine and cosine of real numbers? Yes, they do exist. In fact, sines and cosines of complex numbers also exist. Does that answer the question?
Can trigonometric functions sine cosine and tangent be used in triangles other than right triangles?
Yes, trigonometric functions such as sine, cosine, and tangent can be applied to triangles other than right triangles through the use of the Law of Sines and the Law of Cosines. These laws relate the ratios of the sides of any triangle to the sines and cosines of their angles, allowing for the calculation of unknown sides and angles in non-right triangles. Thus, trigonometric functions are versatile tools applicable to various types of triangles.
