It is proved that the function f (x) = x + 1 / X is an increasing function on [1, + infinite sign] Speed Can you have a look at my other question

It is proved that the function f (x) = x + 1 / X is an increasing function on [1, + infinite sign] Speed Can you have a look at my other question

It is proved that if a and B belong to 1 to positive infinity, b > a can be obtained
Then f (b) - f (a) = B + 1 / b-a-1 / a = B-A + (1 / B-1 / a) = (AB-1) (B-A) / ab
Because AB > 1, b > A, AB > 0, f (b) - f (a) > 0
It is defined as an increasing function
All right~~~

What is sin π / 8 × cos π / 8?

sinπ/8×cosπ/8+cosπ/8×sinπ/8=sinπ/4=√2/2
2sinπ/8×cosπ/8=√2/2
sinπ/8×cosπ/8=√2/4

Sin (a-45 °) is equal to - cos (a + 45 °)
Why is sin (a-45 °) equal to - cos (a + 45 °)

Sina = - cos (a + 90 degrees)
So sin (a-45 °) is equal to - cos (a + 45 °)