Melody

solve the equation. 

\(6 = -4.9t^2 + 14t - 0.4\)

Hint :  it is a quadratic.  Take it all to one side and use the quadratic formula.

The height will be above 6m between the time periods.

And for peats sake no one rush in a give a full answer. 

This forum is supposed to help people learn!

Asker if you have problems you can show what you have done and maybe we will help you more.

Umm not sure.

I have seen that done convincingly before but it is not usual.

I do not think it is worded as a 'proof' but maybe just as 'show'.

You have not used either word in your original question.

I am not familiar with the  sum-to-product  identity.

Well then I do not think you should be working on both sides at once.

You work on one side and show that it is equivalent to the other side.

Please do not delete your questions.  Someone could have been working on it.

Just make a new post saying that you have your answer, but also thank anyone who had already donated any of their time.

You could even give the final answer or an outline of how you solved it.

Maybe someone else will learn from you !

What are you actually trying to do?

I have not checked the last three lines but the rest of the logic looks ok.

BUT what is the question?

Happy Birthday.  Have a great day!  

Oh and thanks for the cake, it is delicious!

Mathematics is used for just about everything.

e.g.  Surveying and cartography is almost solely based on trigonometry.

Engineering is almost entirely maths and physics and the properties of materials.

Without engineering you would have no modern bridges or scyscrapers or airoplanes or just about anything else that makes up our modern existance.

If you want to know EXACTLY how then study hard and the facts will be revealed.

Here is a pic of the flag, it is at the end.

Thanks Chris :)