A
rational number is a number which can be expressed as a fraction whose
numerator and denominator are both integers and whose denominator is not equal
to zero. Rational numbers include all integers, fractions, mixed numbers, and
some decimal numbers.
Note : All terminating and repeating decimal
numbers are rational numbers because those numbers can be expressed as a
fraction. On the other hand, a non repeating number and non terminating
decimal, like square root of 2, is an irrational number.
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Answer:
A 90
Step-by-step explanation:
multiple ways to prove this.
e.g. since the angle between the two lines from the center of the circle to the 2 tangent touching points is 90 degrees (that is the meaning of these 90 degrees here as the angle of the circle segment defined by the 2 tangent touching points and the circle center), the tangents have the same "behavior" as tan and cot = the tangents at the norm circle at 0 and 90 degrees. they hit each other outside of the circle again at 90 degrees.
another way
imagine the two right triangles of the tangents crossing point to the circle center and the tangent/circle touching points.
the Hypotenuse of each triangle is cutting the 90 degree angle of the circle segment exactly in half (due to the symmetry principle). so the angle between radius side and Hypotenuse is 90/2 = 45 degrees.
that means also the angle of such a right triangle at the tangent crossing point is 45 degrees (as the sum of all angles in a triangle must be 180, we have the remainder of 180 - 90 - 45 = 45 degrees).
the angles of both right triangles at that point are the same, and so we can add 45+45 = 90 degrees for the total angle at the tangent crossing point.
Answer:
Mariam went to the store 5 times, while Sana went 3 times.
Step-by-step explanation:
Since Mariam and Sana are excited that a new store just opened in town, and they go together the first day it opens, and each time Mariam goes to the store she plans to spend Rs. 30, and each time Sana goes to the store she plans to spend Rs. 50, and a few weeks from now, Mariam and Sana are surprised to find out that they have spent the exact same total amount of money at the store, to determine what is the least possible number of times that Mariam has been to the store the following mathematical reasoning has to be done:
To know how many times Mariam went and how many times Sana went to the store, since she spends Rs. 30 and the other Rs. 50, and they have spent the same after a few weeks, it is through the search for the lower common multiple of both numbers.
Thus, the common multiple less than 30 and 50 is 150 (30 x 5 or 50 x 3). Therefore, Mariam went to the store 5 times, while Sana went 3 times.
13 is prime because there is only 1 factor 1 and 13.
We'll use the following properties of sine and cosine to prove this:
Then it's just a matter of filling it in...
sin20sin40 * sin60sin80 = 1/2(cos20 - cos60) * 1/2 (cos20 - cos140) =
1/8( cos40 + 1 - cos160 - cos120 - cos40 - cos80 + cos80 + cos200) =
1/8(1 - cos160 - cos120 + cos200) =
1/8(1 - cos160 - cos120 + cos160) =
1/8(1 - cos120 ) = 1/8( 1 + 1/2 ) = 3/16
