Leaving Cert Higher Level Maths 2019, Paper 1 Solutions

In this video I go through the solutions to the leaving certificate maths higher level paper 1. I give a quick read through of each question and it's solution.

[@SwissAirForce335]

For question 2, A(i) why did u sub in 2, could you sub in any number?

[@ziggytheassassin5835]

For Q8 part (a), why did you remove the cos when you wrote out the formula?

[@Aaron_BreadBasket]

I know its basics but I don't get how you added the two fractions in c part (i)

[@saadsyed9838]

At 9:52. In the second line, why don’t you put 2 to the power of a half and then also put (r cos theta + i sin theta) to the power of a half and then solve. If I’m mistaken, when would it be right to power by a half?

[@SimpleScienceandMaths]

That was done without explicitly showing it. From the previous part it was 4 to the power of a half giving 2 etc.

[@conorwalsh3865]

For question 8 b why how did you get the second value (4pie over 3)

[@SimpleScienceandMaths]

Find the inverse cos of -1/2, on your calculator you get 2pi/3, but you need to look at the unit circle to get the second value of 4pi/3. See this link etc.usf.edu/clipart/43200/43215/unit-circle7_43215.htm

[@joelkavanagh5148]

Hi. Thanks for doing these videos they help me a lot. Is this unit circle in the log tables? Or how would I calculate corresponding angles if it isn’t in the log tables? Also, at inspection of the unit circle linked it shows that when you have 2pie/3 it corresponds to 5pie/3, although the answer is 4pie/3. An answer to these questions would be highly appreciated as I’m stuck on this question. Thanks

[@katlynsheehan4289]

For q 8a why did u get rid of the cosine

[@dmeeley8326]

20:54 The linear graph cutting x-axis should be closer to 2.5 no?

[@SimpleScienceandMaths]

Yes you're right, it should be between 2.25 and 2.5 👍

[@dmeeley8326]

16:55 why is n/26(t) = two answers? I only got 2n/3 when doing it and struggled to find the second solution as stated in the question.

[@SimpleScienceandMaths]

Refer back to the unit circle for the second solution when doing trig equations

[@hannahbevan7055]

For q8 part e how do you know that pi/26 t = 0 or pi? Like where are those figures coming from?

[@SimpleScienceandMaths]

the inverse sin of 0 is 0 or pi

[@shanemccormack8817]

@@SimpleScienceandMaths how did you know this though, because if I put in my calculator it will only give one answer

[@SimpleScienceandMaths]

@@shanemccormack8817 you need to use the unit circle. The calculator only gives one answer, the unit circle and CAST gives the other

[@blathnaid6932]

Why does 3/Ln become x^3

[@saadsyed9838]

At 22:15 where does the “y” go?

[@SimpleScienceandMaths]

In the question it says y=(fraction) so sub in the fraction instead of y

[@meganfernane9414]

for question 5 bi how did you get 300

[@rebeccakirwan9686]

You get the tan inverse of -2root3 over 2 and take away from 360

[@tomwhelan7447]

13:08 Why is indefinitely highlighted in bold?

[@SimpleScienceandMaths]

Hi Tom, it's just to emphasise that it's a sum to infinity. I'd say when they were making the question someone felt that it wasn't clear so they put it in bold.

[@williamwang5211]

thanks

[@SimpleScienceandMaths]

You're welcome 👍

[@rhianfitzgerald2657]

you didn't explain question 1 part b properly at all

[@SimpleScienceandMaths]

Yes, i skipped most of the steps but the main part which is how to get rid of the fractions is shown. Give it a go yourself and see if you can get through the steps I skipped and hopefully you get the same answers. If you can do that then you're doing great 👍😎

[@magdalenlawless6355]

Simple Science and Maths I got adifferentanswer to 5c

[@SimpleScienceandMaths]

What did you get? All these solutions and answers are from the official marking scheme from the department.

[@sabrina6707]

@@SimpleScienceandMaths i keep on getting 12x(squared) - 23x - 11 I don't know what I'm doing wrong I got lost after the 3 dots could pls do a video on questions like these or maybe answer this one fully you're doing a great job but I just need you to show me how you got your answer after the 3 dots pls !!!!!!!!!