Trig Question Help

[BlueYoHo]

Perhaps I should have named this thread Trig Questions help... I really dislike this topic. A couple more questions if someone would be so kind as to offer assistance

• Solve, correct to two decimal places, the equation for
• Use the double angle formula for , and the fact that , to find the exact value of
• Equation of area of segment of circle is and the area is . Radius is . Find value of correct to two decimal places.

[TrueTears]

first question whenever something says to x decimal places where (lols) then you use your calculator

same with your third question.

[TrueTears]

now second question



using the tan double angle formula



solving for yields

EDIT: you gotta love those 3D questions ehh XD

[BlueYoHo]

That's what I was doing but I wasn't able to get

Thanks heaps anywayz! I'll get my teach to show me tomorrow

[TrueTears]

so



let

so the equation becomes

factorise and solve for a, you will get 2 answers

but since it must be in the first qudrant so we take the positive answer ie,

[BlueYoHo]

Thanks so much TrueTears, you've really helped.
The problem I was having was factorising it, but my teacher said I could just use the general quadratic equation, the -b plus or minus, etc...
And yeah that worked for me.

But still thanks heaps.

[TrueTears]

Thanks so much TrueTears, you've really helped.
The problem I was having was factorising it, but my teacher said I could just use the general quadratic equation, the -b plus or minus, etc...
And yeah that worked for me.

But still thanks heaps.

Oh yes sorry, I'm an idiot why did i say factorise and solve for 'a' lol(too early in the morning o.O?), i meant use the quadratic formula to solve or complete the square, (asif you can factorise that without calc haha)

[BlueYoHo]

Lol its cool, still appreciate it heaps