Ten thousands place because the dight before the is thousands and the dight after the four is the hundred thousands
y = ( 3 * x ) - 2.
This is because the card costs for 3 $ and should be multiplied by the number of total cards she buys in that particular day. So 3 * x.
Now as she has got a 2$ off coupon, whatever the total is she gets 2 dollars off on that price. So we will subtract 2 at that time. FInally all this summed up would be equal to y.
Double angle formulae involve trigonometric functions of double angles and in order to get its value you must consider the following:
-derive the double angle formula from additional formula
-write the formula for the angle in alternative form
-use the formula to write trigonometric expressions in different forms
-use the formula in the solution of trigonometric equations
And the answer would be 4sin(theta)cos(theta)cos(2theta)