Write each sum using summation notation.
1+ 3 + 5 + 7 + ⋯ + 99

Step-by-step explanation:

First, we need to find the sequence associated to the summation. As you can see the sum only takes odd numbers into account. Hence the sequence it is defined by:

Where:

Now, we only need to find the limits of the summation:

Evaluating n=1

Evaluating n=50

Therefore the summation can be written as:

  21.3

step-by-step explanation:

multiplying the given equation by c/sin(25°), we get

  c = 9/sin(25°) ≈ 21.2958 ≈ 21.3

we assume "c" is the length of ab, the side opposite angle c in triangle abc.