Bac Techniques Mathématiques (Algeria) - independent subject practice cheat sheet

Chain rule: never drop the inner derivative g'(x).

Integration by parts: choose u so du is simpler than u.

Change limits immediately when substituting in a definite integral.

Improper integrals require an explicit limit, not direct substitution.

Implicit differentiation collects dy/dx terms after differentiating both sides.

State domain restrictions before simplifying; cancelled factors still exclude values.

Composition f(g(x)) is evaluated inside-out and is generally not commutative.

Inverses require one-to-one functions; domain and range swap.

Horizontal transformations act opposite to the sign or factor shown.

Log laws convert sums to products, enabling solution of log equations.

Always check candidate solutions against original domain restrictions.

Resolve vectors before applying F = ma or the SUVAT equations

Momentum is a vector: conserve each component only when the corresponding net external impulse is zero

Equilibrium requires both zero resultant force and zero resultant moment

The centripetal component points to the centre; uniform circular motion has constant speed but changing velocity

SHM signature: a = −ω²x, giving T = 2π/ω

State g and sign conventions explicitly at the start of a solution

EMF is per unit charge from the source; terminal p.d. is E − Ir

Kirchhoff's laws follow from conservation of charge and energy

Capacitor energy is ½CV²; discharge is exponential with time constant RC

Magnetic-force magnitude is |q|vB sinθ and its vector is perpendicular to velocity, so magnetic force does no work

n = m/M, n = cV (V in dm3) and n = V/24.0 for gases at RTP are the three key conversions.

The limiting reagent is the one with the smallest moles ÷ coefficient; product amount depends on it.

Percentage yield measures practical success; atom economy measures how much reactant mass is useful.

Dilution uses c1V1 = c2V2 because the moles of solute do not change.

Always balance the equation before applying any molar ratio.

ΔH is negative for exothermic reactions; standard enthalpy of formation of an element in its standard state is zero.

q = mcΔT uses the total mass of solution, and ΔH per mole = −q/n.

Hess's law lets you combine any route; combustion data are used in the reverse order to formation data.

ΔH = Σ bonds broken − Σ bonds formed, and mean bond enthalpies are averages.

Feasibility is determined by ΔG = ΔH − TΔS, not by ΔH alone.

Orders are determined experimentally, not from stoichiometric coefficients.

Rate constant units depend on overall order: for second order overall, dm3 mol−1 s−1; for third order overall, dm6 mol−2 s−1.

In an ideal planar model: pin has two force components, roller one normal reaction, fixed support two force components and a moment.

I = b·h³/12, W = b·h²/6 for a rectangle

Simply supported beam, central load: M_max = F·L/4

Euler: P_cr = π²EI/L_k², with L_k depending on the end conditions

Planar DOF: G = 3(n−1) − 2j₁ − j₂

For the defined ideal lossless gear pair, speed and torque-magnitude ratios are inverse; losses reduce actual output torque.

For a sinusoid V_rms = V_peak/√2; the stated impedance magnitude is for a series RLC model.

Q_C = P(tan φ₁ − tan φ₂) for power-factor correction

Transformer: V₁/V₂ = N₁/N₂ = I₂/I₁

Induction motor: n = (1 − s)·60f/p

Thévenin voltage is open-circuit voltage; deactivate independent sources to obtain resistance while preserving dependent-source behavior.

Karnaugh: give the minimum sum of products

R=d/λ uses thickness in metres; total resistance includes the model’s surfaces and layers.

U=1/R_total is a steady-state element model, not the complete building energy demand.

Permanent, occupancy, wind and snow actions require the stated design framework.

Moisture, airtightness and intended ventilation must be considered together.

Example tie spacing is supplied data, not a code rule.

1 kWh = 3.6 MJ; 1 tep ≈ 41.86 GJ

Conversion efficiency must use a consistent useful output and input; it differs from a heat pump coefficient of performance, which can exceed one.

Carnot heat-engine efficiency is1−T_cold/T_hot using kelvin and the stated hot/cold reservoirs.

Hydro: P = η·ρ·g·Q·H

Wind power grows with v³; Betz limit C_p = 0.593

Sustainability is assessed per kWh: CO₂, life cycle, energy mix

State the system boundary and assumptions before calculation.

Units, sign conventions and uncertainty are part of the answer.

Verification against a specification differs from validation for an intended use.

Drawings need a declared convention and controlled revision.

Classroom models do not authorize physical operation or structural approval.