What is the value of x?
sin 55° = cos x

 The required value of x is 35°.

Step-by-step explanation:  We are given to find the value of x from the following trigonometric equation:

We know that the sine of any acute angle is equal to the cosine of its complement and cosine of any acute angle is equal to the sine of its complement.

So, from equation (i), we get

Thus, the required value of x is 35°.

y = 2x

step-by-step explanation:

if you divide each number in the sequence, you'll see that they all have a multiple factor of 2. each number in the series, and any other numbers which may continue, will be multiplied by 2. therefore, y is the next number in the sequence, and x is the current one, so, our formula will be y = 2x.