# Posts by Shane

Total # Posts: 398

**maths**

Calculate the arc length that subtends an angle of 55 degree at the centre of a circle with radius r = 5cm.

**maths**

The relationship between the vertical height and the horizontal distance of a ball thrown at 45 degree is given by the equation y = x - x^2/50, where y is the vertical height and x is the horizontal distance. (a) Find the maximum vertical height reached. (b) Find the ...

**maths**

The length of a rectangle is 10cm greater than its width. The perimeter of the rectangle is 1m. Find the simplest expression for the perimeter if the width is x.

**Maths**

Find dy/dx if y = 1/8.

**maths**

Does the parabola y = -3x^2 + 2x - 1 have a maximum or minimum value?

**maths**

Find the line that is perpendicular to y = -3/4 x + 2 and passes through (3,4).

**maths**

Sine and Cosine rule are both used in solving trigonometry problems.Give an example of when the cosine rule is more appliciable than the sine rule?

**maths**

Find the two stationary points on the curve when y = 2x/x^2 + 1

**maths**

A circle x^2 + y^ + 2x - 2y -1 = 0 expressed in the following form (x-h)^2 + (y-k)^2 = r^2 where h, k are the coordinates of the centre. How is r the radius given?

**maths**

A circle x^2 + y^ + 2x - 2y -1 = 0 expressed in the following form (x-h)^2 + (y-k)^2 = r^2 where h, k are the coordinates of the centre. How is r the radius given?

**Chemistry**

0.2 Faradays of electricity were passed through solutions of sulphuric acid. Calculate the volume of hydrogen evolved at s.t.p in sulphuric acid.

**Chemistry**

What would be the product formed for electrolysis of copper sulphate between the electrodes (a) Platinum (b) Copper and NaCl (aq) between (a)Platinum and (b) Copper electrodes?

**math**

what are the examples of exponetial notations

**maths**

Find the wind velocity if course 060 degree, airspeed 250km/h; track 040 degree, ground speed 260km/h.

**maths**

Find the course and ground speed if Track 150 degree, airspeed 400km/h; wind 040degree, 30km/h.

**maths**

Find the indicated term for (1-2x)^10, middle term.

**maths**

Find the ratio of the coefficients of the 4th and 6th terms in the expansion of (1 + 2x)^16

**chemistry**

This balance equation shows the burning of octane in air. 2C8H18 + 25O2 ----> 16CO2 + 18H2O. How many grams of carbondioxide will be produced when 1 mole of octane burns completely?

**maths**

Find the expansions of (1-x)^6 and (1+2x)^6 as far as the terms in x^3. Hence expand (1+x-2x^2)^6 up to the terms in x^3.

**maths**

The coefficient of x^2 is 69 in the expansion of (1-ax)^24, where a>0. Find the coefficient of x^3.

**maths**

Expand (1-x)^4. Hence find S if S = (1-x^3)^4 - 4(1-x^3)^3 + 6 (1-x^3)^2 - 4(1-x^3) + 1.

**maths**

In the expansion of (1-2x)^11 the coefficient of x^3 is k times the coefficient of x^2. Evaluate k.

**maths**

Expand (1-6x)^4 (1+2x)^7 in ascending powers of x up to and includeing the terms in x^3.

**maths**

In the expansion of (1-2x)^11 the coefficient of x^3 is k times the coefficient of x^2. Evaluate k.

**maths**

Expand (1+2x)^20 - (1-2x)^20) in ascending powers of x up to the term in x^5 and use this result to evaluate (1.02)^20 - (0.98)^20 to 3 significant figures.

**maths**

Obtain the binomial expansion of (2-x) (1+1/2x)^8 in ascending powers of x as far as the term in x^3. Use your result to estimate the value of 1.9 times (1.05)^8.

**Maths**

Pls help me to show that (1+root x)^5= 10 root x + 20x root x + 2x^2 ]oot x.

**chemistry**

1. In the following reactions, identify which reactants are the oxidizing agent and which are the reducing agents. a. 2S2O32- (aq) + I2 (s) ¨ 2I- (aq) + S4O62- (aq) b. NO3- (aq) + Zn (s) ¨ Zn2+ (aq) + NO2 (g)

**Chemistry**

A solution container was only label 0.005M. When phenolphthalene was added onto the solution, the color of the solution turned pink. After identifying the type of solution,it was later titrated with sodium carbonate. If the solution was sulphuric acid,determine the (a) [H...

**Chemistry**

Determine the [H+] when [OH-] is 2.0 times 10^-2 mole.dm-3.

**maths**

ABC is the segment of a circle with center O. This segment is enclosed in a rectangle APQC. Given that AC = 32 cm and AP = 8 cm, calculate; (a) The radius of the circle. (b) The angle AOC in both degrees and radians. (c) The area of the shaded region.

**Maths**

A surveyor measures the angle of elevation of the top of the mountain from a point (P) at sea level as 30 detre along a track which slopes uniformly uphill towards the mountain. From this point, which is 50 metre above sea level, he measures the angle of elevation as 40 degree...

**Chemistry**

Calculate the [H], [OH], pH and the pOH of this solution; 0.0025 M NaOH

**maths**

The position vector of the point A(3,4) relative to an origin O is a. (a) Express vector a or (OA) in terms of i and j. (b) Find the magnitude of a. (c) Find the unit vector in the direction of a.

**Maths**

ABC is the segment of a circle with center O. This segment is enclosed in a rectangle APQC. Given that AC=32cm and AP = 8 cm, calculate; (a) The radius of the circle. (b) The angle of AOC in both degrees and radians (c) The area of the shaded region.

**maths**

Expand (1-x)^4.Hence find S if S = (1-x^3)^4 - (1-x^3)^3 + 6(1-x^3)^2 - 4(1-x^3) + 1.

**maths**

Find two geometric progressions having: 54 as third term and 27/32 as ninth term.

**Maths**

Find the total amount required to pay off a loan of 16000 plus interest at the end of 8 years if the interest is compounded half-yearly and the rate is 14% p.a.

**Maths**

The third term of a sequence is 2(2/3) and the sixth term is 9. Find the first six terms when the sequence is; (a) arithmetic (b) geometric

**Maths**

Given the f (x) =2x^3 + ax^2 + bx - 9. (a)Find the value of a and b if f (x) has a factor x -3 but leaves a reminder of 8 when divided by x + 1. (b) Factorize f (x) completely and hence solve for x.

**maths**

If the nth term of a sequence is 3 x 2^n-1, Write down the first three terms.

**maths**

Find two geometric progression having: 2 as second term and 1458 as eight term,

**Chemistry**

One step of the Ostwald process for manufacturing nitric acid involves making nitrogen monoxide by oxidizing ammonia in the presence of a platinum catalyst: 4NH3 (g) + 502 (g)>> 4NO (g) + 6H2O (g). If the percentage yield is 80.3%, how many grams of NO can be produced ...

**Chemistry**

When 9.08 times 10^5 grams (one ton) of sodium chloride are electrolyzed in the commerical production of Chlorine, 5.24 times 10^5 grams of Chlorine are produced: 2 NaCl (aq) + 2 H2O (l) >>H2 (g) + Cl2 (g) + 2 NaOH (aq). Calculate the percentage yield.

**Chemistry**

When 9.08 times 10^5 grams (one ton) of sodium chloride are electrolyzed in the commerical production of Chlorine, 5.24 times 10^5 grams of Chlorine are produced: 2 NaCl (aq) + 2 H2O (l) >>H2 (g) + Cl2 (g) + 2 NaOH (aq). Calculate the percentage yield.

**MATHS - URGENT**

Write the expression in terms of sine only. 8(sin 2x − cos 2x)

**math**

tan(180-x)sin(360-x)cos90-x)cos(-x)/sin(x-180)cos(450+x)tan(180-x)

**7th math**

I just printed ine of them. 5 pages. Helpful thanks and I saved the other site.

**7th math**

Thanks too.

**7th math**

I'm having a hard time remembering these inequalities. DO you know of a site on the internet for me to practice?

**7th math**

I have no more than five books in my bag. I need to write an inequality for this, x<5 ?

**math**

Your favorite breakfast cereal contains a toy dinosaur in each box. There are four different dinosaur toys in the complete collection, and each one has an equal chance of being in each box. You want to figure out what the probability is that you will get more than one ...

**math**

2005 2006 2007 2008 Plant 1 20 4 25 10 Plant 2 25 5 5 48 Plant 3 20 8 20 32 Plant 4 43 10 10 47 Plant 5 40 11 15 48 A gardener recorded how many tomatoes 5 plants produced each year. Which year had the LARGEST interquartile range of tomatoes produced? A) 2005 B) 2006 C) 2007 D...

**Math**

Is that the answer or what I have x< =5.5 then i line on a number line half between 4 and 5 going left on a closed circle. Right?

**maths**

solve this equation. log (2x + 1) base 2 = -3

**maths**

Solve this logarithmic equation. 3 log 2 base x + log 18 base x = 2

**maths**

Solve this logarithmic equation. 3 log 2 base x + log 18 base x = 2

**maths**

Solve this equation. 3^2x - 3^x+2 = 3^x - 9

**maths**

Proof this identities. (a) sin x cot x = cos x

**maths**

Please I need help.Show full working out. (a) sin x cot x= cos x (b) (1 + tan theta)^2 + (1- tan theta)^2 = 2sec^2theta

**maths**

Please help me simplify this and show full working out. (a) (2x^3 divide 3y^4)^2 multiply (x divide 3y)^-2 (b) a-a^-1 divide a^2 - 1 (c) 3^a+2 times 9^2a+1 divide by 6^2 times 3^5a+3

**Maths**

Ship A is 18.5km from a port P on a beearing of 045 degree and ship B is 26.4km from point P on a bearing of 105 degree. Calculate the bearing of A from B and the distance AB.

**Maths**

Please help me.Iam stuck. Find all the possible values of theta between 0 degree and 360 degree for the following quadratic equation. State the quadrants in which each angle lie. 8 tan^2 theta + 2 tan theta=15

**Maths**

Please help me.Iam stuck. Find all the possible values of theta between 0 degree and 360 degree for the following quadratic equation. State the quadrants in which each angle lie. 8 tan^2 theta + 2 tan theta=15

**Maths**

AB is a 12 metre flagpole on top of a building. Given angle QPB=56 degree 37' and angle QPA=43 degree 19',find the distance of PB.

**Maths**

A and B are two balloons at the same height and 1000 metre apart. O is a ground observation position. Angle AOX is 45 degree 15' and angle BOX is 10 degree and 30'. Find the height of the balloons.

**Maths**

Find the area of the triangle with sides 8.6 cm, 9.1cm and 9.7cm. First find the size of one of the angles.

**Maths**

An aircraft which is maintaining a constant altitude of 1000 metre is travelling directly away from an observer. At a particular instant the angle of elevation is 52 degree and 12 seconds later the angle of elevation is 16 degree. Find the distance travelled in this time.

**Maths**

Please I need help.Iam stuck with this question.Using sine and cosine rule: A rocket launced vertically from L is observed from A. Soon after launch when at position M its angle of elevation is 25 degree. After it climbs 4000m from this position to N its angle of elevation is ...

**Maths**

Please help me. P and Q are two gun placements 1250m apart. T is a target. The angles TPQ and TQP are 73 degree 24' and 68 degree 5' respectively. Find the distance P to the target T.

**Maths**

Iam stuck.Please anyone help me. P and Q are two trees 490m apart beside a river. F is a flagpole on the other side of the river. If angle PQF=43 degree and angle QFP = 36 degree, Find the distance PF.

**Maths**

A and B are on the opposite side of tower.

**Maths**

A tower T is observed from two points A and B which are 240 metres apart. The angle TAB is found to be 57degree and the angle TBA is 78degree. Find the distance of the tower from A.

**HELP Physics**

The average rate at which energy is conducted outward through the ground surface in a certain region is 30.9 mW/m2, and the average thermal conductivity of the near-surface rocks is 3.11 W/m·K. Assuming a surface temperature of 9.48°C, find the temperature (in ...

**maths**

Iam stuck with this question.Please anyone help me. An airplane is flying at an altitude of 10,000m.The pilot sees two ships A and B.Ship A is due south of P and 22.5km away(in a direct line).Likewise ship B is due East and 40.8km from P. The height is 10km. Find the distance ...

**Maths**

Find all the values of theta between 0 degree and 360 degree, and state the quadrants in which they exist. (a)cos theta=-0.71 (b)tan theta=1.732

**Biology**

What are some of the treatments for coronary artery disease?

**Biology**

Explain what happens when a person with AB+ donates blood to a patient with A+ blood type?

**Biology**

Explain the role of white blood cells in the body's defense against foreign substances.

**maths**

From an observer 0, the angles of elevation to the bottom and top of the flag pole are 36 degree and 38 degree respectively. The base is 200m. Find the height of the flag pole.

**maths**

From an observer 0, the angles of elevation to the bottom and top of the flag pole are 36 degree and 38 degree respectively. The base is 200m. Find the height of the flag pole.

**maths**

Using the complementary angle ratio results,find the value of x for the following. (a) cos(x+35)degree=sin x degree (b) sec x degree=cosec(x+20)degree

**maths**

An airplane is flying at an altitude of 10,000m. The pilot sees two ships A and B. Ship A is due south of P and 22.5km away (in a direct line).Likewise ship B is due East and 40.8km from P. Find the distance between the two ships.

**Maths**

An aeroplane flies due north for 200 km and then turns due east and flies for a further distance of 325km. Find the bearing,to the nearest degree,of the aeroplane from its starting point.

**Maths**

Using the exact trigonometric ratios of 45 degree,30 degree and 60 degree,evaluate the following,leaving where necessary your answer in surd form. (a) 3 sin 30 degree-2 cos 60 degree (b)(tan 45 degree)(4 cos 60 degree-2 cos 60 degree)

**math**

c=Cost m=miles c=$3.00+(m*$2.00) If the number of miles=1 c=$3.00+(1*$2.00) c=$3.00+$2.00 c=$5.00

**6th grade Math**

A sample of 50 people in Harrisburg indicates that 10 people of them know the name of the mayor of their neighboring city. Out of 5, 500 Harrisburgh residents, how many would you expect to know the name of the mayor of the neighboring city?

**Art Ms. Sue please**

thye are right

**CHEM**

mass of C in sample = mass of C in CO2 mass of C in sample = (0.8635 g CO2 / 44 g/mol)(1 mol C / 1 mol CO2)(12 g/mol) = 0.2355 g mass of H in sample = mass of H in H2O mass of H in sample = (0.1767 g H2O / 18 g/mol)(2 mol H / 1 mol H2O)(1 g/mol) = 0.0196 g mass of O in sample...

**CHEM**

A 0.4647-g sample of a compound known to contain only carbon, hydrogen, and oxygen was burned in oxygen to yield 0.8635 g of CO2 and 0.1767 g of H2O. What is the empirical formula of the compound? i got C3H3O2 IS IT RIGHT?

**Chemistry**

WHATS THE GRAM OF H2O THEN?

**Chemistry**

oh nvmd yes the LR is O2

**chem**

COULD YOU PLS EXPLAIN IT TO ME.

**chem**

Consider the fermentation reaction of glucose: C6H12O6 ----) 2C2H5OH+2CO2 A 1.00-mol sample of C6H12O6 was placed in a vat with excess yeast. If 35.1 g of C2H5OH was obtained, what was the percent yield of C2H5OH?

**maths**

An observer on top of a building 66 metres high,finds the angle of elevation to the top of a taller building to be 34 degrees.The angle of depression to the foot of the same building is 51 degrees.If the buildings are on the same ground level find the height of the taller ...

**maths**

Find the area of an equilateral triangle whose base is 10 cm.

**Chemistry**

(1) Use the thermodynamic values to (a) deduce the enthalpy change of each reaction (b)state if the reaction is exothermic,or endothermic,and also how much energy is released or absorbed. For thi reactions; (1) NH4NO3 (s)------>N2 (g) + 2H2O (l) (2) 4Zn (s) + 9HNO3 (aq...

**Maths**

From a point on a lighthouse 76 metres above sea level,the angle of depression of a fishing boat 28 degrees.How far is the boat from the foot of the lighthouse?

**maths**

A surveyor finds two points A and B on a hillside to be 114.6 metres apart(measured along the line of sight) and finds the angle of elevation from A to B to be 21 degrees.On his plans these points must be shown at their horizontal distance apart.Find this distance.

**Maths**

The top of a T .V .tower casts a shadow 35 metres long when the angle of elevation of the sun 57 degree40 minutes.How high is the top of the tower?