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ABC is a right angled triangle. D is the point on AB such that AD = 3DB. AC = 2DB and angle A = 90 degrees. Show that sinC = k/√20 where k is an integer. Find the value of k

AB = 4DB AC = 2DB Find BC using Pythagoras: BC = √(4DB) 2 + (2DB) 2 BC = √20DB 2 = √20 DB sinC = opp/hyp = 4DB/√20DB = 4/√20 so k = 4
TJ
Answered by Tom J. • Maths tutor
16517 Views

How do I start my answer?

Before you start writing, make sure you know what you’re going to say. Take ten minutes to do a rough plan. Often the best place to start is the wording of the title – it will focus what you say on the quest...
LN
5505 Views

What is democracy?

The term ‘democracy’ derives from the Greek word, “demokratia”, which can be translated simply as ‘rule by the people’. It is used to describe a system of government that allows people to have an influence o...
GL
8550 Views

Solve 7(k – 3) = 3k – 5

Step 1: 7k-21=3k-5 Step 2: 4k=16 Step 3: k=4
JY
Answered by Jin Yang Q. • Maths tutor
7879 Views

Solve the equation 3x squared + 4x – 12 = 0 Give your solutions correct to 2 decimal places.

3x 2 +4x-12=0 Step 1: formula (-b+/- square root (b 2 -4ac))/2a Step 2: a=3 b=4 c=-12 Step 3: type into your calculator Step 4: answer 1.44, or -2.77
JY
Answered by Jin Yang Q. • Maths tutor
17672 Views